Stundenplan: Wochenend-Flakiness in Unterrichtsmodus-Test behoben

OpenWeekCell_LessonHeuteWaehrendUnterrichtszeit_OeffnetUnterrichtsmodus schlug
an Sa/So fehl, weil today.DayOfWeek dort keiner Kachel im Mo-Fr-Wochenraster
entspricht. TimetableViewModel bekommt dafür eine austauschbare Clock-Property
(Standard: DateTime.Now), sodass der Test "heute" unabhängig vom tatsächlichen
Wochentag simulieren kann.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

CLAUDE.md

@@ -60,12 +60,16 @@ The API can also run via `docker/docker-compose.yml` (reads `JWT_SECRET` from th
   orchestration, timer-driven), `SnapshotService`, `Crypto/SyncCrypto` (AES-256-GCM payload
   encryption — desktop events are encrypted at rest and in transit; Companion/WebApp events are
   plaintext, see `PlainSyncEvent` vs `SyncEvent`).
+- **LehrerApp.WebUntis** — direkter, serverunabhängiger WebUntis-Client für den Desktop. Hält die
+  persönliche JSON-RPC-Sitzung lokal und parst den Schülerreport lokal; WebUntis-Zugangsdaten und
+  personenbezogene Antworten dürfen nicht über `LehrerApp.Api` geleitet werden.
 - **LehrerApp.Api** — minimal ASP.NET Core server: JWT auth, an append-only `EventStore` plus
   `SnapshotStore`/`ReadableSnapshotStore` per device, mapped in `Endpoints/Endpoints.cs`. Sync is
   optional — Desktop only registers `SyncEngine`/`SnapshotService` in DI when a server URL is
   configured (`AppBootstrapper.LoadServerUrl`).
 - Each library has a matching `*.Tests` project (`LehrerApp.Tests` → Core, `LehrerApp.Data.Tests` →
   Data, `LehrerApp.Desktop.Tests` → Desktop, `LehrerApp.Sync.Tests` → Sync), all xUnit.
+  `LehrerApp.WebUntis.Tests` covers the direct WebUntis client and report parser.
 
 ### MVVM conventions (Desktop)
 

LehrerApp.Api/Endpoints/Endpoints.cs

@@ -1,6 +1,7 @@
 using System.IdentityModel.Tokens.Jwt;
 using System.Security.Claims;
 using System.Text;
+using System.Globalization;
 using LehrerApp.Core.Models;
 using LehrerApp.Sync.Models;
 using Microsoft.AspNetCore.Mvc;

LehrerApp.Api/EventStore.cs

@@ -1,4 +1,5 @@
 using LiteDB;
+using LehrerApp.Sync;
 using LehrerApp.Sync.Models;
 
 namespace LehrerApp.Api;
@@ -67,7 +68,7 @@ public class EventStore(string dataPath) : IDisposable
     {
         var col    = GetCol(userId);
         var events = col.Find(e => e.ServerSeq > since && e.DeviceId != requestingDeviceId)
-            .OrderBy(e => e.ServerSeq).Take(500)
+            .OrderBy(e => e.ServerSeq).Take(SyncProtocol.PullBatchSize)
             .Select(e => new SyncEvent { EventId = e.EventId, DeviceId = e.DeviceId,
                 DeviceType = e.DeviceType, Timestamp = e.Timestamp,
                 SequenceNr = e.ServerSeq, EntityType = e.EntityType,

LehrerApp.Core/Interfaces/IRepositories.cs

@@ -136,6 +136,40 @@ public interface IUntisSnapshotRepository
     void Save(UntisSnapshotEntry entry);
     void Delete(Guid id);
 }
+/// Lokaler Cache der Fehlzeiten-Berichtszeilen fürs Klassenlehrer-Feature (siehe TODO.md) —
+/// bewusst nicht synchronisiert (siehe Implementierung), jedes Gerät ruft WebUntis selbst ab.
+public interface IUntisAbsenceCacheRepository
+{
+    List<UntisAbsenceCacheEntry> GetByClassAndRange(string className, int startDate, int endDate);
+    /// Löscht vorhandene Zeilen im Bereich und fügt die übergebenen neu ein — fürs "heiße" Fenster,
+    /// dessen Inhalt sich seit dem letzten Abruf geändert haben kann.
+    void ReplaceRange(string className, int startDate, int endDate, IEnumerable<UntisAbsenceCacheEntry> entries);
+    /// Fügt nur ein, ohne zu löschen — fürs Erweitern der als endgültig angenommenen "kalten" Historie.
+    void InsertRange(IEnumerable<UntisAbsenceCacheEntry> entries);
+}
+/// Lokaler Cache der Klassenbuch-Berichtszeilen anderer Lehrkräfte fürs Klassenlehrer-Feature —
+/// gleiches Muster wie <see cref="IUntisAbsenceCacheRepository"/>.
+public interface IUntisClassRegisterCacheRepository
+{
+    List<UntisClassRegisterCacheEntry> GetByClassAndRange(string className, int startDate, int endDate);
+    void ReplaceRange(string className, int startDate, int endDate, IEnumerable<UntisClassRegisterCacheEntry> entries);
+    void InsertRange(IEnumerable<UntisClassRegisterCacheEntry> entries);
+}
+/// Lokaler Cache der aktuellen Klassenliste (Roster) fürs Klassenlehrer-Feature — anders als
+/// Fehlzeiten/Klassenbuch keine Historie, deshalb kein ReplaceRange/InsertRange, sondern immer der
+/// komplette Ersatz des zuletzt bekannten Standes einer Klasse.
+public interface IUntisStudentRosterCacheRepository
+{
+    List<UntisStudentRosterCacheEntry> GetByClass(string className);
+    void ReplaceAll(string className, IEnumerable<UntisStudentRosterCacheEntry> entries);
+}
+/// Merkt sich je Klasse+Berichtsart, wann das heiße Fenster zuletzt aufgefrischt wurde und wie weit
+/// die kalte Historie bereits abgedeckt ist (siehe UntisReportCacheService).
+public interface IUntisCacheFetchStateRepository
+{
+    UntisCacheFetchState? Get(string className, UntisCacheKind kind);
+    void Save(UntisCacheFetchState state);
+}
 /// Vom Nutzer bestätigte Zuordnungen WebUntis-Wochenmuster → LearningGroup.
 public interface IUntisSlotMappingRepository
 {

LehrerApp.Core/Models/Exam.cs

@@ -13,6 +13,12 @@ public class Exam
     public DateOnly? ReturnedAt { get; set; }
     public Niveau? Niveau { get; set; }
     public string? Notes { get; set; }
+    public DateOnly? ApprovalGrantedAt { get; set; }
+    public DateOnly? AnnouncedAt { get; set; }
+    /// Verknüpft Parallelklausuren (gleiche Arbeit, mehrere Kurse) für den Kurs-Umschalter
+    /// auf der Klausuren-Hauptseite — Id der "Ursprungs"-Klausur, gesetzt beim Duplizieren
+    /// (siehe ExamDialogViewModel.Save).
+    public Guid? SharedExamGroupId { get; set; }
     public DateTime CreatedAt { get; set; } = DateTime.UtcNow;
     public DateTime UpdatedAt { get; set; } = DateTime.UtcNow;
 }

LehrerApp.Core/Models/LearningGroup.cs

@@ -20,6 +20,12 @@ public class LearningGroup
     /// deaktivierbar - blendet die Erinnerung "Ungeplante Stunden" im Dashboard für diese Gruppe aus.
     /// </summary>
     public bool RequiresLessonPlanning { get; set; } = true;
+    /// <summary>
+    /// WebUntis-interne Unterrichtsnummer (lsid) dieser Lerngruppe, Grundlage für den Abruf des
+    /// "Fehlzeiten pro Unterricht"-Berichts. Wird von WebUntis pro Schuljahr neu vergeben und muss
+    /// deshalb händisch je Lerngruppe/Schuljahr gepflegt werden - keine JSON-RPC-Methode liefert sie.
+    /// </summary>
+    public int? WebUntisLessonId { get; set; }
     public DateTime CreatedAt { get; set; } = DateTime.UtcNow;
     public DateTime UpdatedAt { get; set; } = DateTime.UtcNow;
 }

LehrerApp.Core/Models/UntisCache.cs

@@ -0,0 +1,79 @@
+namespace LehrerApp.Core.Models;
+
+/// <summary>
+/// Lokal zwischengespeicherte Zeile aus dem WebUntis-Bericht "Fehlzeiten pro Schüler*in"
+/// (Klassenlehrer-Feature, siehe TODO.md) — 1:1-Abbildung von `UntisClassAbsenceEntryDto`
+/// (LehrerApp.Desktop), damit Fehlzeiten nicht bei jedem Öffnen der Ansicht neu abgerufen werden
+/// müssen. <c>Date</c> bewusst als <c>int</c> (yyyyMMdd) wie die DTOs statt <c>DateOnly</c>/
+/// <c>DateTime</c> — vermeidet die LiteDB-<c>DateTime</c>-Kind-Tücke (siehe CLAUDE.md) und ist
+/// direkt für Bereichs-Queries nutzbar.
+/// </summary>
+public class UntisAbsenceCacheEntry
+{
+    public Guid Id { get; set; } = Guid.NewGuid();
+    public string ClassName { get; set; } = "";
+    public string StudentName { get; set; } = "";
+    public int? ExternKey { get; set; }
+    public int Date { get; set; }
+    public int AbsentPeriods { get; set; }
+    public int AbsentMinutes { get; set; }
+    public string? TeacherUsernames { get; set; }
+    public string? Subject { get; set; }
+    public string? AbsenceReason { get; set; }
+    public string? Note { get; set; }
+    public int? EntryId { get; set; }
+    public string? HandledOn { get; set; }
+    public bool Counts { get; set; }
+    public string? ExcuseNote { get; set; }
+    public int? PeriodNumber { get; set; }
+    public string? Status { get; set; }
+    public bool CountsAsFullDay { get; set; }
+}
+
+/// <summary>Lokal zwischengespeicherte Zeile aus dem "-alle-"-Klassenbuchbericht, gefiltert auf
+/// Einträge anderer Lehrkräfte (Klassenlehrer-Feature) — 1:1-Abbildung von
+/// `UntisForeignClassRegisterEventDto` (LehrerApp.Desktop).</summary>
+public class UntisClassRegisterCacheEntry
+{
+    public Guid Id { get; set; } = Guid.NewGuid();
+    public string ClassName { get; set; } = "";
+    public int Date { get; set; }
+    public string? Subject { get; set; }
+    public string StudentName { get; set; } = "";
+    public string? TeacherUsername { get; set; }
+    public string? CategoryName { get; set; }
+    public string? CategoryGroup { get; set; }
+    public string? Text { get; set; }
+}
+
+/// <summary>Lokal zwischengespeicherte Zeile aus dem WebUntis-Schülerreport, eingeschränkt auf die
+/// für die Klassenlehrer-Übersicht nötigen Felder (Roster-Namen) — anders als Fehlzeiten/
+/// Klassenbuch keine Historie, sondern immer nur der zuletzt abgerufene Stand einer Klasse
+/// (siehe <see cref="UntisClassRegisterCacheEntry"/> für den Grund, warum es trotzdem ein eigenes
+/// Modell statt Wiederverwendung des vollen Schülerreport-DTOs ist: nur diese zwei Felder werden
+/// für den Roster-Abgleich tatsächlich gebraucht).</summary>
+public class UntisStudentRosterCacheEntry
+{
+    public Guid Id { get; set; } = Guid.NewGuid();
+    public string ClassName { get; set; } = "";
+    public int? ExternKey { get; set; }
+    public string DisplayName { get; set; } = "";
+}
+
+public enum UntisCacheKind { Absences, ClassRegister, Roster }
+
+/// <summary>
+/// Ein Datensatz pro (<see cref="ClassName"/>, <see cref="Kind"/>): wann das "heiße" Fenster
+/// (die letzten Tage, deren Status sich noch ändern kann) zuletzt aufgefrischt wurde, und wie weit
+/// die "kalte", als endgültig angenommene Historie bereits lückenlos zurückreicht. Getrennt von den
+/// Cache-Zeilen selbst, weil ein Fenster ohne Treffer (z.B. eine ereignislose Woche) sonst keine
+/// Zeile hinterließe, aus der sich "zuletzt abgerufen am…" ableiten ließe.
+/// </summary>
+public class UntisCacheFetchState
+{
+    public Guid Id { get; set; } = Guid.NewGuid();
+    public string ClassName { get; set; } = "";
+    public UntisCacheKind Kind { get; set; }
+    public DateTime? HotWindowFetchedAt { get; set; }
+    public int? ColdCoverageStartDate { get; set; }
+}

LehrerApp.Core/Models/Workload.cs

@@ -24,6 +24,10 @@ public class Documentation : IHasAttachments
     /// <summary>Im Unterricht schnell erfasst und noch inhaltlich nachzuarbeiten.</summary>
     public bool IsDraft { get; set; }
     public bool IsConfidential { get; set; }
+    /// <summary>Für die pädagogische Arbeit/Leistungsbewertung gedacht, aber nicht für den
+    /// WebUntis-Klassenbuch-Abgleich vorgesehen - blendet den Eintrag im Abgleichsdialog
+    /// (WebUntisDocumentationComparisonViewModel) aus dem Zwischenablage-Vorschlag aus.</summary>
+    public bool ExcludeFromWebUntisSync { get; set; }
     public DateTime CreatedAt { get; set; } = DateTime.UtcNow;
     public DateTime UpdatedAt { get; set; } = DateTime.UtcNow;
     // Löschen entfernt den Eintrag nicht hart, sondern markiert ihn nur (Nachvollziehbarkeit, 5.1.4).

LehrerApp.Core/Services/ExamPriorityService.cs

@@ -0,0 +1,67 @@
+using LehrerApp.Core.Models;
+
+namespace LehrerApp.Core.Services;
+
+/// Zählt den Korrekturfortschritt einer Klausur aus den vorhandenen Ergebnissen, statt einen
+/// eigenen "Korrektur läuft"-Status pflegen zu müssen — ein `ExamResult` gilt als erledigt, sobald
+/// entweder Punkte/Note eingetragen oder der Schüler als abwesend markiert wurde. Von
+/// DashboardViewModel (Karte "Offene Korrekturen") und ExamsOverviewViewModel (Klausuren-
+/// Hauptseite) gemeinsam genutzt, damit beide Stellen exakt dieselbe Zahl zeigen.
+public static class ExamCorrectionCounter
+{
+    public static (int Expected, int Evaluated) Count(Exam exam, List<GroupMembership> groupMemberships,
+        List<ExamResult> examResults)
+    {
+        var expected = groupMemberships.Count(m => GroupMembershipService.IsActiveOn(m, exam.Date));
+        var evaluated = examResults.Count(r => r.Absent || !string.IsNullOrWhiteSpace(r.Grade) || r.Points.Count > 0);
+        return (expected, Math.Min(evaluated, expected));
+    }
+}
+
+public enum ExamListStatus { Planned, AwaitingCorrection, CorrectionInProgress, CorrectionStuck, AwaitingReturn, Returned }
+
+public readonly record struct ExamPriorityInfo(ExamListStatus Status, double Score);
+
+/// Ordnet Klausuren für die Klausuren-Hauptseite nach einem unsichtbaren Prioritäts-Score statt
+/// nach Datum: unbearbeitete/überfällige Korrekturen oben, erledigte unten. "Korrektur läuft"
+/// wird bewusst nicht als eigener, manuell zu pflegender Status abgelegt (siehe
+/// `ExamCorrectionCounter`) — bleibt eine Klausur trotzdem lange in Bearbeitung hängen (typischer
+/// Grund: ein einzelner nie nachschreibender Schüler), fällt sie nach `StuckAfterDays` aus der
+/// dringenden Zone in eine ruhige "hängt fest"-Einstufung, statt dauerhaft oben zu kleben.
+public static class ExamPriorityService
+{
+    public const int StuckAfterDays = 21;
+    private const int CorrectionGraceDays = 3;
+
+    public static ExamPriorityInfo Evaluate(Exam exam, int expected, int evaluated, DateOnly today)
+    {
+        if (exam.Status == ExamStatus.Returned)
+            return new ExamPriorityInfo(ExamListStatus.Returned, -100);
+
+        if (exam.Status == ExamStatus.Graded)
+            return new ExamPriorityInfo(ExamListStatus.AwaitingReturn, 300);
+
+        if (exam.Status == ExamStatus.Planned)
+        {
+            var daysUntil = exam.Date.DayNumber - today.DayNumber;
+            return new ExamPriorityInfo(ExamListStatus.Planned, Math.Clamp(150 - daysUntil, 20, 150));
+        }
+
+        // Status == Conducted: Korrekturfortschritt entscheidet über die genaue Einstufung.
+        var daysSince = today.DayNumber - exam.Date.DayNumber;
+
+        if (evaluated <= 0)
+        {
+            var score = daysSince <= CorrectionGraceDays ? 400 + daysSince * 10 : 600 + daysSince;
+            return new ExamPriorityInfo(ExamListStatus.AwaitingCorrection, score);
+        }
+
+        if (expected > 0 && evaluated >= expected)
+            return new ExamPriorityInfo(ExamListStatus.AwaitingReturn, 300);
+
+        if (daysSince > StuckAfterDays)
+            return new ExamPriorityInfo(ExamListStatus.CorrectionStuck, 90);
+
+        return new ExamPriorityInfo(ExamListStatus.CorrectionInProgress, 400 + daysSince * 3);
+    }
+}

LehrerApp.Core/Services/GroupRolloverService.cs

@@ -60,6 +60,8 @@ public sealed class GroupRolloverService(
             IsActive = true,
             IsOwnClass = source.IsOwnClass,
             IsDifferentiated = source.IsDifferentiated,
+            // WebUntisLessonId bewusst nicht übernommen: WebUntis vergibt sie pro Schuljahr neu,
+            // eine übernommene alte lsid würde in der Folgegruppe stumm falsche Fehlzeiten liefern.
         };
 
         var sourceWasActive = source.IsActive;

LehrerApp.Data.Tests/RepositoryTests.cs

@@ -1053,6 +1053,101 @@ public sealed class RepositoryTests
         Assert.Equal("fahrt", repo.GetByExternalId("fahrt")!.ExternalId);
     }
 
+    // ── UntisAbsenceCacheRepository / UntisClassRegisterCacheRepository / UntisCacheFetchStateRepository ──
+
+    [Fact]
+    public void UntisAbsenceCacheRepository_GetByClassAndRange_FiltertKlasseUndDatumsbereich()
+    {
+        using var db = NewInMemoryContext();
+        var repo = new UntisAbsenceCacheRepository(db);
+        repo.InsertRange(
+        [
+            new UntisAbsenceCacheEntry { ClassName = "10c", StudentName = "Max", Date = 20260824 },
+            new UntisAbsenceCacheEntry { ClassName = "10c", StudentName = "Max", Date = 20260901 },
+            new UntisAbsenceCacheEntry { ClassName = "10d", StudentName = "Ben", Date = 20260824 },
+        ]);
+
+        var result = repo.GetByClassAndRange("10c", 20260801, 20260831);
+
+        Assert.Single(result);
+        Assert.Equal(20260824, result[0].Date);
+    }
+
+    [Fact]
+    public void UntisAbsenceCacheRepository_ReplaceRange_ErsetztNurDenAngegebenenBereich()
+    {
+        using var db = NewInMemoryContext();
+        var repo = new UntisAbsenceCacheRepository(db);
+        repo.InsertRange(
+        [
+            new UntisAbsenceCacheEntry { ClassName = "10c", StudentName = "Alt", Date = 20260810 },
+            new UntisAbsenceCacheEntry { ClassName = "10c", StudentName = "Alt", Date = 20260901 },
+        ]);
+
+        repo.ReplaceRange("10c", 20260801, 20260831,
+            [new UntisAbsenceCacheEntry { ClassName = "10c", StudentName = "Neu", Date = 20260815 }]);
+
+        var inRange = repo.GetByClassAndRange("10c", 20260801, 20260831);
+        var untouched = repo.GetByClassAndRange("10c", 20260901, 20260901);
+        Assert.Equal("Neu", Assert.Single(inRange).StudentName);
+        Assert.Single(untouched);
+    }
+
+    [Fact]
+    public void UntisClassRegisterCacheRepository_InsertUndGetByClassAndRange_RoundTrip()
+    {
+        using var db = NewInMemoryContext();
+        var repo = new UntisClassRegisterCacheRepository(db);
+        repo.InsertRange([new UntisClassRegisterCacheEntry
+        {
+            ClassName = "10c", Date = 20260824, StudentName = "Max", Subject = "Deu",
+            TeacherUsername = "mueller", CategoryName = "Positiv",
+        }]);
+
+        var result = Assert.Single(repo.GetByClassAndRange("10c", 20260801, 20260831));
+        Assert.Equal("mueller", result.TeacherUsername);
+    }
+
+    [Fact]
+    public void UntisStudentRosterCacheRepository_ReplaceAll_ErsetztNurDieAngegebeneKlasse()
+    {
+        using var db = NewInMemoryContext();
+        var repo = new UntisStudentRosterCacheRepository(db);
+        repo.ReplaceAll("10c", [new UntisStudentRosterCacheEntry { ClassName = "10c", DisplayName = "Alt" }]);
+        repo.ReplaceAll("10d", [new UntisStudentRosterCacheEntry { ClassName = "10d", DisplayName = "Andere Klasse" }]);
+
+        repo.ReplaceAll("10c", [new UntisStudentRosterCacheEntry { ClassName = "10c", DisplayName = "Neu", ExternKey = 42 }]);
+
+        var tenC = repo.GetByClass("10c");
+        var tenD = repo.GetByClass("10d");
+        Assert.Equal("Neu", Assert.Single(tenC).DisplayName);
+        Assert.Equal(42, tenC[0].ExternKey);
+        Assert.Single(tenD); // andere Klasse bleibt unberührt
+    }
+
+    [Fact]
+    public void UntisCacheFetchStateRepository_SaveUndGet_RoundTripJeKlasseUndArt()
+    {
+        using var db = NewInMemoryContext();
+        var repo = new UntisCacheFetchStateRepository(db);
+        var fetchedAt = new DateTime(2026, 8, 25, 10, 0, 0, DateTimeKind.Utc);
+        repo.Save(new UntisCacheFetchState
+        {
+            ClassName = "10c", Kind = UntisCacheKind.Absences,
+            HotWindowFetchedAt = fetchedAt, ColdCoverageStartDate = 20260101,
+        });
+
+        var result = repo.Get("10c", UntisCacheKind.Absences);
+        var missing = repo.Get("10c", UntisCacheKind.ClassRegister);
+
+        Assert.NotNull(result);
+        // LiteDB rundet Kind Utc->Local, verschiebt dabei die Ticks um denselben Zeitpunkt zu
+        // erhalten (siehe CLAUDE.md) - deshalb erst beide Seiten auf UTC normalisieren.
+        Assert.Equal(fetchedAt.ToUniversalTime(), result!.HotWindowFetchedAt!.Value.ToUniversalTime());
+        Assert.Equal(20260101, result.ColdCoverageStartDate);
+        Assert.Null(missing);
+    }
+
     // ── WorkTaskRepository ────────────────────────────────────────────────────
 
     [Fact]

LehrerApp.Data/LiteDbContext.cs

@@ -68,6 +68,10 @@ public class LiteDbContext : IDisposable
     public ILiteCollection<SubstitutionEntry> SubstitutionEntries => _db.GetCollection<SubstitutionEntry>("substitution_entries");
     public ILiteCollection<UntisSnapshotEntry> UntisSnapshotEntries => _db.GetCollection<UntisSnapshotEntry>("untis_snapshot_entries");
     public ILiteCollection<UntisSlotMapping> UntisSlotMappings => _db.GetCollection<UntisSlotMapping>("untis_slot_mappings");
+    public ILiteCollection<UntisAbsenceCacheEntry> UntisAbsenceCache => _db.GetCollection<UntisAbsenceCacheEntry>("untis_absence_cache");
+    public ILiteCollection<UntisClassRegisterCacheEntry> UntisClassRegisterCache => _db.GetCollection<UntisClassRegisterCacheEntry>("untis_classregister_cache");
+    public ILiteCollection<UntisCacheFetchState> UntisCacheFetchStates => _db.GetCollection<UntisCacheFetchState>("untis_cache_fetch_state");
+    public ILiteCollection<UntisStudentRosterCacheEntry> UntisStudentRosterCache => _db.GetCollection<UntisStudentRosterCacheEntry>("untis_student_roster_cache");
     public ILiteCollection<AnnualPlanEvent> AnnualPlanEvents => _db.GetCollection<AnnualPlanEvent>("annual_plan_events");
     public ILiteCollection<TrashedItem>    TrashedItems    => _db.GetCollection<TrashedItem>("trash");
 
@@ -535,6 +539,13 @@ public class LiteDbContext : IDisposable
         AnnualPlanEvents.EnsureIndex(x => x.ExternalId, unique: true);
         AnnualPlanEvents.EnsureIndex(x => x.StartDate);
         AnnualPlanEvents.EnsureIndex(x => x.EndDate);
+        UntisAbsenceCache.EnsureIndex(x => x.ClassName);
+        UntisAbsenceCache.EnsureIndex(x => x.Date);
+        UntisClassRegisterCache.EnsureIndex(x => x.ClassName);
+        UntisClassRegisterCache.EnsureIndex(x => x.Date);
+        UntisStudentRosterCache.EnsureIndex(x => x.ClassName);
+        UntisCacheFetchStates.EnsureIndex("ux_class_kind",
+            BsonExpression.Create("STRING($.ClassName) + ':' + STRING($.Kind)"), unique: true);
     }
 
     public void Dispose() => _db.Dispose();

LehrerApp.Data/Repositories/AllRepositories.cs

@@ -794,6 +794,65 @@ public class AnnualPlanEventRepository(LiteDbContext db) : IAnnualPlanEventRepos
     public void Delete(Guid id) => db.AnnualPlanEvents.Delete(id);
 }
 
+// Wie UntisSnapshotEntry/AnnualPlanEvent rein lokal, bewusst kein db.OnChange: Fehlzeiten- und
+// Klassenbuch-Cache fürs Klassenlehrer-Feature (siehe TODO.md) wachsen über ein Schuljahr auf viele
+// hundert Zeilen an - über Sync würde das nur Rauschen erzeugen, und jedes Gerät ruft WebUntis
+// ohnehin selbst ab (siehe UntisReportCacheService).
+public class UntisAbsenceCacheRepository(LiteDbContext db) : IUntisAbsenceCacheRepository
+{
+    public List<UntisAbsenceCacheEntry> GetByClassAndRange(string className, int startDate, int endDate) =>
+        db.UntisAbsenceCache
+          .Find(e => e.ClassName == className && e.Date >= startDate && e.Date <= endDate)
+          .ToList();
+
+    public void ReplaceRange(string className, int startDate, int endDate, IEnumerable<UntisAbsenceCacheEntry> entries)
+    {
+        db.UntisAbsenceCache.DeleteMany(e => e.ClassName == className && e.Date >= startDate && e.Date <= endDate);
+        db.UntisAbsenceCache.InsertBulk(entries);
+    }
+
+    public void InsertRange(IEnumerable<UntisAbsenceCacheEntry> entries) => db.UntisAbsenceCache.InsertBulk(entries);
+}
+
+public class UntisClassRegisterCacheRepository(LiteDbContext db) : IUntisClassRegisterCacheRepository
+{
+    public List<UntisClassRegisterCacheEntry> GetByClassAndRange(string className, int startDate, int endDate) =>
+        db.UntisClassRegisterCache
+          .Find(e => e.ClassName == className && e.Date >= startDate && e.Date <= endDate)
+          .ToList();
+
+    public void ReplaceRange(string className, int startDate, int endDate, IEnumerable<UntisClassRegisterCacheEntry> entries)
+    {
+        db.UntisClassRegisterCache.DeleteMany(e => e.ClassName == className && e.Date >= startDate && e.Date <= endDate);
+        db.UntisClassRegisterCache.InsertBulk(entries);
+    }
+
+    public void InsertRange(IEnumerable<UntisClassRegisterCacheEntry> entries) => db.UntisClassRegisterCache.InsertBulk(entries);
+}
+
+// Gleiches "bewusst kein db.OnChange"-Prinzip wie UntisAbsenceCacheRepository oben, auch wenn der
+// Roster selbst klein bleibt (aktuelle Klassenliste, keine Historie) - jedes Gerät ruft ihn ohnehin
+// selbst ab.
+public class UntisStudentRosterCacheRepository(LiteDbContext db) : IUntisStudentRosterCacheRepository
+{
+    public List<UntisStudentRosterCacheEntry> GetByClass(string className) =>
+        db.UntisStudentRosterCache.Find(e => e.ClassName == className).ToList();
+
+    public void ReplaceAll(string className, IEnumerable<UntisStudentRosterCacheEntry> entries)
+    {
+        db.UntisStudentRosterCache.DeleteMany(e => e.ClassName == className);
+        db.UntisStudentRosterCache.InsertBulk(entries);
+    }
+}
+
+public class UntisCacheFetchStateRepository(LiteDbContext db) : IUntisCacheFetchStateRepository
+{
+    public UntisCacheFetchState? Get(string className, UntisCacheKind kind) =>
+        db.UntisCacheFetchStates.FindOne(s => s.ClassName == className && s.Kind == kind);
+
+    public void Save(UntisCacheFetchState state) => db.UntisCacheFetchStates.Upsert(state);
+}
+
 public class CompetencyDomainRepository(LiteDbContext db) : ICompetencyDomainRepository
 {
     public List<CompetencyDomain> GetBySubjectAndGrade(Guid subjectId, int gradeLevel) =>

LehrerApp.Desktop.Tests/ClassTeacherViewModelsTests.cs

@@ -0,0 +1,412 @@
+using LehrerApp.Core.Models;
+using LehrerApp.Desktop.Services;
+using LehrerApp.Desktop.ViewModels.ClassTeacher;
+using Xunit;
+
+namespace LehrerApp.Desktop.Tests;
+
+public sealed class ClassTeacherViewModelsTests
+{
+    [Fact]
+    public void GroupByStudentAndDay_FasstFehlstundenProSchuelerUndTagZusammen()
+    {
+        var entries = new[]
+        {
+            new UntisClassAbsenceEntryDto("Muster Max", 1, "6a", 20260824, 1, 45, "HED", "Che", "Absent",
+                "Krank", 1, "24.08.26", true, null, 3, "nicht entsch.", false),
+            new UntisClassAbsenceEntryDto("Muster Max", 1, "6a", 20260824, 1, 45, "PAN", "Kunst", null,
+                "Krank", 2, "24.08.26", true, null, 5, "nicht entsch.", true),
+            new UntisClassAbsenceEntryDto("Andere Schuelerin", 2, "6a", 20260824, 1, 20, "BEN", "Deu",
+                "Verspätung", null, 3, "24.08.26", false, "Zug verpasst", 1, "entsch.", false),
+        };
+
+        var rows = ClassAbsenceDaySummaryRow.GroupByStudentAndDay(entries);
+
+        Assert.Equal(2, rows.Count);
+
+        var max = rows[1];
+        Assert.Equal("Muster Max", max.StudentName);
+        Assert.Equal(2, max.TotalAbsentPeriods);
+        Assert.Equal(90, max.TotalAbsentMinutes);
+        Assert.Equal(["Che", "Kunst"], max.Subjects);
+        Assert.Equal([3, 5], max.PeriodNumbers.Order());
+        Assert.Equal(["nicht entsch."], max.Statuses);
+        Assert.Equal(["Absent"], max.AbsenceReasons);
+        Assert.Equal("Krank", max.Note);
+        Assert.Null(max.ExcuseNote);
+        Assert.True(max.CountsAsFullDay);
+
+        var andere = rows[0];
+        Assert.Equal("Andere Schuelerin", andere.StudentName);
+        Assert.Equal(1, andere.TotalAbsentPeriods);
+        Assert.Equal(20, andere.TotalAbsentMinutes);
+        Assert.Equal(["Deu"], andere.Subjects);
+        Assert.Null(andere.Note);
+        Assert.Equal("Zug verpasst", andere.ExcuseNote);
+        Assert.False(andere.CountsAsFullDay);
+    }
+
+    [Fact]
+    public void GroupByStudentAndDay_TrenntGleichenNamenAnUnterschiedlichenTagen()
+    {
+        var entries = new[]
+        {
+            new UntisClassAbsenceEntryDto("Muster Max", 1, "6a", 20260824, 1, 45, "HED", "Che", null,
+                null, 1, "24.08.26", true, null, 3, "nicht entsch.", false),
+            new UntisClassAbsenceEntryDto("Muster Max", 1, "6a", 20260825, 1, 45, "HED", "Che", null,
+                null, 2, "25.08.26", true, null, 3, "nicht entsch.", false),
+        };
+
+        var rows = ClassAbsenceDaySummaryRow.GroupByStudentAndDay(entries);
+
+        Assert.Equal(2, rows.Count);
+        Assert.Equal(new DateOnly(2026, 8, 25), rows[0].Date);
+        Assert.Equal(new DateOnly(2026, 8, 24), rows[1].Date);
+    }
+
+    [Fact]
+    public void RosterBuild_OrdnetFehlzeitPerExternKeyUndKlassenbuchPerNameZu()
+    {
+        var students = new[]
+        {
+            Student(1001, "Ada Müller"),
+            Student(1002, "Ben Schmidt"),
+            Student(1003, "Cem Yilmaz"),
+        };
+        var todayAbsences = new[]
+        {
+            new ClassAbsenceDaySummaryRow(new DateOnly(2026, 8, 25), "Ada Müller", 1001, 2, 90,
+                ["Che"], [3, 4], ["nicht entsch."], ["Absent"], null, null, false),
+        };
+        var recentClassRegister = new[]
+        {
+            new UntisForeignClassRegisterEventDto("6a", 20260824, "Deu", "Ben Schmidt", "mueller",
+                "Vergessen", "Organisation", "Buch vergessen"),
+        };
+
+        var roster = ClassTeacherRosterRow.Build(students, todayAbsences, recentClassRegister);
+
+        Assert.Equal(3, roster.Count);
+        var ada = Assert.Single(roster, r => r.StudentName == "Ada Müller");
+        Assert.True(ada.HasAbsenceToday);
+        Assert.Contains("nicht entsch.", ada.AbsenceTooltip);
+        Assert.False(ada.HasRecentClassRegisterEntry);
+
+        var ben = Assert.Single(roster, r => r.StudentName == "Ben Schmidt");
+        Assert.False(ben.HasAbsenceToday);
+        Assert.True(ben.HasRecentClassRegisterEntry);
+
+        var cem = Assert.Single(roster, r => r.StudentName == "Cem Yilmaz");
+        Assert.False(cem.HasAbsenceToday);
+        Assert.False(cem.HasRecentClassRegisterEntry);
+    }
+
+    [Fact]
+    public void RosterBuild_ErkenntNamenAuchInVertauschterReihenfolge()
+    {
+        // WebUntis liefert Namen im Schülerreport als "Vorname Nachname", in Fehlzeiten-/
+        // Klassenbuchberichten aber typischerweise als "Nachname Vorname" - der Namensabgleich
+        // muss das auch ohne ExternKey erkennen (Regressionstest für genau diesen Bug).
+        var students = new[] { Student(externKey: null, displayName: "Ben Schmidt") };
+        var todayAbsences = new[]
+        {
+            new ClassAbsenceDaySummaryRow(new DateOnly(2026, 8, 25), "Schmidt Ben", null, 1, 45,
+                ["Che"], [3], ["nicht entsch."], ["Absent"], null, null, false),
+        };
+        var recentClassRegister = new[]
+        {
+            new UntisForeignClassRegisterEventDto("6a", 20260824, "Deu", "Schmidt Ben", "mueller",
+                "Vergessen", "Organisation", "Buch vergessen"),
+        };
+
+        var roster = ClassTeacherRosterRow.Build(students, todayAbsences, recentClassRegister);
+
+        var ben = Assert.Single(roster);
+        Assert.True(ben.HasAbsenceToday);
+        Assert.True(ben.HasRecentClassRegisterEntry);
+    }
+
+    [Fact]
+    public void RosterBuild_BeschreibtVerspaetungNichtAlsNullFehlstunden()
+    {
+        var students = new[] { Student(1001, "Ada Müller") };
+        var todayAbsences = new[]
+        {
+            new ClassAbsenceDaySummaryRow(new DateOnly(2026, 8, 26), "Müller Ada", 1001, 0, 20,
+                ["Deu"], [1], ["nicht entsch."], ["Verspätung"], null, null, false),
+        };
+
+        var row = Assert.Single(ClassTeacherRosterRow.Build(students, todayAbsences, [],
+            new DateOnly(2026, 8, 26)));
+
+        Assert.True(row.IsLate);
+        Assert.True(row.IsUnexcused);
+        Assert.Equal("20 Min. verspätet · Unentschuldigt", row.StatusText);
+        Assert.Equal(ClassTeacherStatusKind.Danger, row.StatusKind);
+    }
+
+    [Fact]
+    public void RosterBuild_PriorisiertHandlungsbedarfVorUnauffaelligenSchuelern()
+    {
+        var students = new[]
+        {
+            Student(1001, "Zora Unauffällig"),
+            Student(1002, "Ada Fehlzeit"),
+            Student(1003, "Ben Klassenbuch"),
+        };
+        var absences = new[]
+        {
+            new ClassAbsenceDaySummaryRow(new DateOnly(2026, 8, 26), "Fehlzeit Ada", 1002, 2, 90,
+                ["Deu"], [1, 2], ["nicht entsch."], ["Absent"], null, null, false),
+        };
+        var register = new[]
+        {
+            new UntisForeignClassRegisterEventDto("10c", 20260825, "Deu", "Klassenbuch Ben", "test",
+                "Fehlende HA", "Negativ", "Hausaufgaben fehlen"),
+        };
+
+        var rows = ClassTeacherRosterRow.Build(students, absences, register, new DateOnly(2026, 8, 26));
+
+        Assert.Equal(["Ada Fehlzeit", "Ben Klassenbuch", "Zora Unauffällig"],
+            rows.Select(r => r.StudentName));
+    }
+
+    [Fact]
+    public void RosterBuild_BerechnetFehlquoteSeitSchuljahresbeginn()
+    {
+        var students = new[] { Student(1001, "Ada Müller") };
+        var yearAbsences = new[]
+        {
+            new ClassAbsenceDaySummaryRow(new DateOnly(2026, 8, 10), "Müller Ada", 1001, 2, 90,
+                ["Che"], [1, 2], ["entsch."], ["Krank"], null, null, false),
+            new ClassAbsenceDaySummaryRow(new DateOnly(2026, 8, 17), "Müller Ada", 1001, 6, 270,
+                ["Che"], [1, 2, 3, 4, 5, 6], ["nicht entsch."], ["Absent"], null, null, true),
+        };
+
+        var row = Assert.Single(ClassTeacherRosterRow.Build(students, [], [],
+            new DateOnly(2026, 8, 26), yearAbsences, schoolDaysElapsed: 20));
+
+        Assert.True(row.HasYearSummary);
+        Assert.Equal(2, row.YearAbsenceDayCount);
+        Assert.Equal(1, row.YearUnexcusedDayCount);
+        Assert.Equal(10, row.YearAbsenceRatePercent);
+        Assert.Contains("10 %", row.YearSummaryLabel);
+        Assert.Contains("2 von 20", row.YearSummaryTooltip);
+        Assert.Contains("1 unentschuldigt", row.YearSummaryTooltip);
+    }
+
+    [Fact]
+    public void RosterBuild_OhneJahresdatenZeigtKeineFehlquote()
+    {
+        var students = new[] { Student(1001, "Ada Müller") };
+
+        var row = Assert.Single(ClassTeacherRosterRow.Build(students, [], [], new DateOnly(2026, 8, 26)));
+
+        Assert.False(row.HasYearSummary);
+        Assert.Equal("", row.YearSummaryLabel);
+        Assert.Null(row.YearSummaryTooltip);
+    }
+
+    [Fact]
+    public void RosterBuild_OrdnetJahresfehlzeitenAuchOhneExternKeyUeberNamenZu()
+    {
+        var students = new[] { Student(externKey: null, displayName: "Ben Schmidt") };
+        var yearAbsences = new[]
+        {
+            new ClassAbsenceDaySummaryRow(new DateOnly(2026, 8, 10), "Schmidt Ben", null, 2, 90,
+                ["Che"], [1, 2], ["entsch."], ["Krank"], null, null, false),
+        };
+
+        var row = Assert.Single(ClassTeacherRosterRow.Build(students, [], [], new DateOnly(2026, 8, 26),
+            yearAbsences, schoolDaysElapsed: 10));
+
+        Assert.Equal(1, row.YearAbsenceDayCount);
+    }
+
+    [Fact]
+    public void TrendDay_AnteileSummierenSichZurGesamtquote()
+    {
+        var day = new ClassTeacherTrendDay("Mo", 5, 2, 1, 2, 0.4d, 0.2d, 0.4d);
+
+        Assert.Equal(1.0d, day.TotalFraction, precision: 10);
+    }
+
+    [Fact]
+    public void RosterBuild_StelltGefahrUndWarnungMitSymbolVoran()
+    {
+        var students = new[] { Student(1001, "Ada Müller"), Student(1002, "Ben Schmidt") };
+        var todayAbsences = new[]
+        {
+            new ClassAbsenceDaySummaryRow(new DateOnly(2026, 8, 26), "Müller Ada", 1001, 2, 90,
+                ["Che"], [1, 2], ["nicht entsch."], ["Absent"], null, null, false),
+            new ClassAbsenceDaySummaryRow(new DateOnly(2026, 8, 26), "Schmidt Ben", 1002, 2, 90,
+                ["Che"], [1, 2], ["entsch."], ["Absent"], null, null, false),
+        };
+
+        var roster = ClassTeacherRosterRow.Build(students, todayAbsences, [], new DateOnly(2026, 8, 26));
+
+        var ada = Assert.Single(roster, r => r.StudentName == "Ada Müller");
+        Assert.Equal(ClassTeacherStatusKind.Danger, ada.StatusKind);
+        Assert.StartsWith("✕ ", ada.StatusTextWithGlyph);
+
+        var ben = Assert.Single(roster, r => r.StudentName == "Ben Schmidt");
+        Assert.Equal(ClassTeacherStatusKind.Warning, ben.StatusKind);
+        Assert.StartsWith("△ ", ben.StatusTextWithGlyph);
+    }
+
+    [Fact]
+    public void RosterBuild_LaesstUnauffaelligenStatusOhneSymbol()
+    {
+        var students = new[] { Student(1001, "Zora Unauffällig") };
+
+        var row = Assert.Single(ClassTeacherRosterRow.Build(students, [], [], new DateOnly(2026, 8, 26)));
+
+        Assert.Equal(row.StatusText, row.StatusTextWithGlyph);
+    }
+
+    // ── Offene Entschuldigungen (Feature-Idee 2) ─────────────────────────────
+
+    [Fact]
+    public void OpenExcuseBuild_SortiertNachTagenOffenAbsteigendUndIgnoriertEntschuldigte()
+    {
+        var absences = new[]
+        {
+            new ClassAbsenceDaySummaryRow(new DateOnly(2026, 8, 20), "Alt Ada", 1001, 2, 90,
+                ["Che"], [1, 2], ["nicht entsch."], ["Absent"], null, null, false),
+            new ClassAbsenceDaySummaryRow(new DateOnly(2026, 8, 25), "Neu Ben", 1002, 1, 45,
+                ["Deu"], [1], ["nicht entsch."], ["Absent"], null, null, false),
+            new ClassAbsenceDaySummaryRow(new DateOnly(2026, 8, 24), "Entschuldigt Cem", 1003, 1, 45,
+                ["Deu"], [1], ["entsch."], ["Absent"], null, null, false),
+        };
+
+        var rows = ClassTeacherOpenExcuseRow.Build(absences, new DateOnly(2026, 8, 26));
+
+        // StudentName kommt aus StudentDisplayName (WebUntis liefert "Nachname Vorname",
+        // hier für die Anzeige auf "Vorname Nachname" gedreht - siehe ClassAbsenceDaySummaryRow).
+        Assert.Equal(["Ada Alt", "Ben Neu"], rows.Select(r => r.StudentName));
+        Assert.Equal(6, rows[0].DaysOpen);
+        Assert.True(rows[0].IsOverdue);
+        Assert.Equal(1, rows[1].DaysOpen);
+        Assert.False(rows[1].IsOverdue);
+    }
+
+    // ── Aggregierte Klassenbuch-Kategorien (Feature-Idee 5) ──────────────────
+
+    [Fact]
+    public void CategoryAggregateBuild_ZaehltProKategorieUndNenntTopSchueler()
+    {
+        var entries = new[]
+        {
+            new ClassTeacherClassRegisterRow(new DateOnly(2026, 8, 20), "Deu", "Schmidt Ben", "test",
+                "Hausaufgaben fehlen", "Negativ", "HA fehlt"),
+            new ClassTeacherClassRegisterRow(new DateOnly(2026, 8, 21), "Deu", "Schmidt Ben", "test",
+                "Hausaufgaben fehlen", "Negativ", "HA fehlt"),
+            new ClassTeacherClassRegisterRow(new DateOnly(2026, 8, 22), "Che", "Müller Ada", "test",
+                "Hausaufgaben fehlen", "Negativ", "HA fehlt"),
+            new ClassTeacherClassRegisterRow(new DateOnly(2026, 8, 23), "Che", "Müller Ada", "test",
+                "Lob", "Positiv", "Gute Mitarbeit"),
+        };
+
+        var rows = ClassTeacherCategoryAggregateRow.Build(entries);
+
+        Assert.Equal(["Hausaufgaben fehlen", "Lob"], rows.Select(r => r.CategoryName));
+        var homework = rows[0];
+        Assert.Equal(3, homework.Count);
+        Assert.Contains("2× Ben Schmidt", homework.TopStudentsLabel);
+        Assert.Contains("1× Ada Müller", homework.TopStudentsLabel);
+    }
+
+    // ── Erweiterte Mustererkennung: Wochentags-Häufung (Feature-Idee 4) ──────
+
+    [Fact]
+    public void DetectWeekdayPatterns_ErkenntDeutlicheHaeufungAnEinemWochentag()
+    {
+        // 24.08./31.08.2026 und 07.09.2026 sind allesamt Montage.
+        var absences = new[]
+        {
+            new ClassAbsenceDaySummaryRow(new DateOnly(2026, 8, 24), "Muster Mona", 1001, 1, 45,
+                ["Deu"], [1], ["entsch."], ["Absent"], null, null, false),
+            new ClassAbsenceDaySummaryRow(new DateOnly(2026, 8, 31), "Muster Mona", 1001, 1, 45,
+                ["Deu"], [1], ["entsch."], ["Absent"], null, null, false),
+            new ClassAbsenceDaySummaryRow(new DateOnly(2026, 9, 7), "Muster Mona", 1001, 1, 45,
+                ["Deu"], [1], ["entsch."], ["Absent"], null, null, false),
+        };
+        var names = new Dictionary<string, string> { [UntisNameMatching.NameKey("Muster Mona")] = "Mona Muster" };
+
+        var notices = ClassTeacherOverviewViewModel.DetectWeekdayPatterns(
+            absences, names, new HashSet<string>());
+
+        var notice = Assert.Single(notices);
+        Assert.Equal("Mona Muster", notice.StudentName);
+        Assert.Contains("Montag", notice.Message);
+        Assert.Equal(ClassTeacherStatusKind.Info, notice.Kind);
+    }
+
+    [Fact]
+    public void DetectWeekdayPatterns_IgnoriertZuKleineStichprobe()
+    {
+        var absences = new[]
+        {
+            new ClassAbsenceDaySummaryRow(new DateOnly(2026, 8, 24), "Muster Mona", 1001, 1, 45,
+                ["Deu"], [1], ["entsch."], ["Absent"], null, null, false),
+            new ClassAbsenceDaySummaryRow(new DateOnly(2026, 8, 31), "Muster Mona", 1001, 1, 45,
+                ["Deu"], [1], ["entsch."], ["Absent"], null, null, false),
+        };
+
+        var notices = ClassTeacherOverviewViewModel.DetectWeekdayPatterns(
+            absences, new Dictionary<string, string>(), new HashSet<string>());
+
+        Assert.Empty(notices);
+    }
+
+    [Fact]
+    public void DetectWeekdayPatterns_LaesstBereitsGemeldeteSchuelerAus()
+    {
+        var absences = new[]
+        {
+            new ClassAbsenceDaySummaryRow(new DateOnly(2026, 8, 24), "Muster Mona", 1001, 1, 45,
+                ["Deu"], [1], ["entsch."], ["Absent"], null, null, false),
+            new ClassAbsenceDaySummaryRow(new DateOnly(2026, 8, 31), "Muster Mona", 1001, 1, 45,
+                ["Deu"], [1], ["entsch."], ["Absent"], null, null, false),
+            new ClassAbsenceDaySummaryRow(new DateOnly(2026, 9, 7), "Muster Mona", 1001, 1, 45,
+                ["Deu"], [1], ["entsch."], ["Absent"], null, null, false),
+        };
+        var names = new Dictionary<string, string> { [UntisNameMatching.NameKey("Muster Mona")] = "Mona Muster" };
+
+        var notices = ClassTeacherOverviewViewModel.DetectWeekdayPatterns(
+            absences, names, new HashSet<string> { "Mona Muster" });
+
+        Assert.Empty(notices);
+    }
+
+    // ── Noten-/Mitarbeit-Brücke: Namensabgleich (Feature-Idee 7) ─────────────
+
+    [Fact]
+    public void MatchStudent_FindetUeberVorUndNachnameTrotzKommaInFullName()
+    {
+        // Student.FullName liefert "Nachname, Vorname" (mit Komma) - ein Abgleich darüber würde
+        // UntisNameMatching.NameKey verfälschen ("Müller," bliebe eigenes Wort). MatchStudent
+        // muss deshalb FirstName/LastName getrennt verwenden, nicht FullName.
+        var students = new List<Student>
+        {
+            new() { FirstName = "Ada", LastName = "Müller" },
+            new() { FirstName = "Ben", LastName = "Schmidt" },
+        };
+
+        var match = ClassTeacherOverviewViewModel.MatchStudent("Müller Ada", students);
+
+        Assert.NotNull(match);
+        Assert.Equal("Ada", match!.FirstName);
+    }
+
+    [Fact]
+    public void MatchStudent_LiefertNullOhneTreffer()
+    {
+        var students = new List<Student> { new() { FirstName = "Ada", LastName = "Müller" } };
+
+        Assert.Null(ClassTeacherOverviewViewModel.MatchStudent("Unbekannt Xyz", students));
+    }
+
+    private static UntisStudentRosterCacheEntry Student(int? externKey, string displayName) =>
+        new() { ClassName = "6a", ExternKey = externKey, DisplayName = displayName };
+}

LehrerApp.Desktop.Tests/DashboardViewModelTests.cs

@@ -11,6 +11,22 @@ namespace LehrerApp.Desktop.Tests;
 /// (offene Aufgaben, ...).
 public sealed class DashboardViewModelTests
 {
+    [Fact]
+    public void LeereHinweisbereiche_WerdenAusgeblendetUndZusammenfassungBleibtKompakt()
+    {
+        var group = new LearningGroup { Name = "9c" };
+        var today = DateOnly.FromDateTime(DateTime.Today);
+
+        var vm = BuildVm(group, new Lesson { GroupId = group.Id, Date = today });
+
+        Assert.False(vm.ExcusesCard.EffectiveIsVisible);
+        Assert.False(vm.CorrectionsCard.EffectiveIsVisible);
+        Assert.False(vm.AlertsCard.EffectiveIsVisible);
+        Assert.Equal("0 offene Punkte", vm.AttentionSummary);
+        Assert.True(vm.TodayCard.EffectiveIsVisible);
+        Assert.True(vm.CalendarCard.EffectiveIsVisible);
+    }
+
     private static PeriodScheduleService NewPeriodSchedule()
     {
         var tempPath = System.IO.Path.Combine(

LehrerApp.Desktop.Tests/ExamGradingDialogViewModelTests.cs

@@ -0,0 +1,65 @@
+using LehrerApp.Core.Models;
+using LehrerApp.Core.Services;
+using LehrerApp.Desktop.ViewModels.Groups;
+using Xunit;
+
+namespace LehrerApp.Desktop.Tests;
+
+/// Deckt 1.6.3 (Bulk-Aktion "Rest als abwesend markieren") ab — löst das Nutzer-Feedback, dass
+/// Schüler, die nie nachschreiben, sonst dauerhaft eine leere, unberührte Zeile hinterlassen.
+public sealed class ExamGradingDialogViewModelTests
+{
+    [Fact]
+    public void MarkRemainingAbsent_MarktNurUnberührteZeilenAbwesend()
+    {
+        var group = new LearningGroup { Name = "Q1 Chemie" };
+        var studentWithPoints = new Student { FirstName = "Anna", LastName = "Bauer" };
+        var untouchedStudent1 = new Student { FirstName = "Ben", LastName = "Cordes" };
+        var untouchedStudent2 = new Student { FirstName = "Cara", LastName = "Diehl" };
+        var students = new FakeStudents([studentWithPoints, untouchedStudent1, untouchedStudent2]);
+        var memberships = new FakeMemberships(
+        [
+            new GroupMembership { GroupId = group.Id, StudentId = studentWithPoints.Id },
+            new GroupMembership { GroupId = group.Id, StudentId = untouchedStudent1.Id },
+            new GroupMembership { GroupId = group.Id, StudentId = untouchedStudent2.Id },
+        ]);
+        var exam = new Exam
+        {
+            GroupId = group.Id,
+            Title = "Klausur 1",
+            Tasks = [new ExamTask { Nr = 1, MaxPoints = 10 }],
+            GradingKey = GradingService.DefaultKey1To6(),
+        };
+        var results = new FakeResults();
+
+        var vm = new ExamGradingDialogViewModel(results, students, memberships,
+            new GradingService(), exam, group.Id);
+
+        var rowWithPoints = vm.Rows.Single(r => r.StudentId == studentWithPoints.Id);
+        rowWithPoints.Cells[0].TrySetValue(7);
+
+        vm.MarkRemainingAbsentCommand.Execute(null);
+
+        Assert.False(rowWithPoints.Absent);
+        Assert.True(vm.Rows.Single(r => r.StudentId == untouchedStudent1.Id).Absent);
+        Assert.True(vm.Rows.Single(r => r.StudentId == untouchedStudent2.Id).Absent);
+    }
+
+    [Fact]
+    public void MarkRemainingAbsent_LässtBereitsAbwesendMarkierteUnverändert()
+    {
+        var group = new LearningGroup { Name = "Q1 Chemie" };
+        var student = new Student { FirstName = "Ben", LastName = "Cordes" };
+        var students = new FakeStudents([student]);
+        var memberships = new FakeMemberships(
+            [new GroupMembership { GroupId = group.Id, StudentId = student.Id }]);
+        var exam = new Exam { GroupId = group.Id, Title = "Klausur 1", Tasks = [new ExamTask { Nr = 1, MaxPoints = 10 }], GradingKey = GradingService.DefaultKey1To6() };
+        var vm = new ExamGradingDialogViewModel(new FakeResults(), students, memberships,
+            new GradingService(), exam, group.Id);
+
+        vm.Rows[0].Absent = true;
+        vm.MarkRemainingAbsentCommand.Execute(null);
+
+        Assert.True(vm.Rows[0].Absent);
+    }
+}

LehrerApp.Desktop.Tests/ExamsOverviewViewModelTests.cs

@@ -0,0 +1,89 @@
+using LehrerApp.Core.Models;
+using LehrerApp.Core.Services;
+using LehrerApp.Desktop.ViewModels.Exams;
+using Xunit;
+
+namespace LehrerApp.Desktop.Tests;
+
+/// Deckt 1.6 (Klausuren-Hauptseite) ab: Priorisierung end-to-end über die ViewModel-Schicht,
+/// Parallelkurs-Umschalter (1.6.4) und Genehmigung/Ankündigung (1.6.5).
+public sealed class ExamsOverviewViewModelTests
+{
+    private static ExamsOverviewViewModel BuildVm(List<LearningGroup> groups, List<Exam> exams,
+        FakeMemberships? memberships = null, FakeResults? results = null) =>
+        new(new FakeExams(exams), results ?? new FakeResults(), new FakeGroups(groups),
+            memberships ?? new FakeMemberships([]), new GradingService(), new SchoolYearService());
+
+    [Fact]
+    public void Load_UnbearbeiteteKorrekturStehtVorGeplanterKlausur()
+    {
+        var group = new LearningGroup { Name = "Q1 Chemie", SchoolYear = new SchoolYearService().CurrentSchoolYear() };
+        var today = DateOnly.FromDateTime(DateTime.Today);
+        var overdue = new Exam { GroupId = group.Id, Title = "Alte Klausur", Status = ExamStatus.Conducted, Date = today.AddDays(-10) };
+        var planned = new Exam { GroupId = group.Id, Title = "Neue Klausur", Status = ExamStatus.Planned, Date = today.AddDays(3) };
+
+        var vm = BuildVm([group], [overdue, planned]);
+        vm.LoadCommand.Execute(null);
+
+        Assert.Equal("Alte Klausur", vm.Rows[0].Title);
+        Assert.Equal("Neue Klausur", vm.Rows[1].Title);
+    }
+
+    [Fact]
+    public void Load_ParallelkurseWerdenAlsGeschwisterErkannt()
+    {
+        var groupA = new LearningGroup { Name = "Chemie GK Q1", SchoolYear = new SchoolYearService().CurrentSchoolYear() };
+        var groupB = new LearningGroup { Name = "Chemie GK Q1b", SchoolYear = groupA.SchoolYear };
+        var original = new Exam { GroupId = groupA.Id, Title = "Redox", Status = ExamStatus.Planned, Date = DateOnly.FromDateTime(DateTime.Today).AddDays(5) };
+        var duplicate = new Exam
+        {
+            GroupId = groupB.Id, Title = "Redox", Status = ExamStatus.Planned,
+            Date = DateOnly.FromDateTime(DateTime.Today).AddDays(6), SharedExamGroupId = original.Id,
+        };
+
+        var vm = BuildVm([groupA, groupB], [original, duplicate]);
+        vm.LoadCommand.Execute(null);
+
+        vm.SelectedRow = vm.Rows.Single(r => r.Exam.Id == original.Id);
+        Assert.True(vm.SelectedRow.HasSibling);
+        Assert.Single(vm.Siblings);
+        Assert.Equal(duplicate.Id, vm.Siblings[0].Exam.Id);
+    }
+
+    [Fact]
+    public void ToggleApproval_SetztUndLöschtDatum()
+    {
+        var group = new LearningGroup { Name = "Q1 Chemie", SchoolYear = new SchoolYearService().CurrentSchoolYear() };
+        var exam = new Exam { GroupId = group.Id, Title = "Klausur", Status = ExamStatus.Planned, Date = DateOnly.FromDateTime(DateTime.Today).AddDays(2) };
+        var vm = BuildVm([group], [exam]);
+        vm.LoadCommand.Execute(null);
+        vm.SelectedRow = vm.Rows[0];
+
+        vm.ToggleApprovalCommand.Execute(null);
+        Assert.NotNull(exam.ApprovalGrantedAt);
+        Assert.StartsWith("Genehmigt am", vm.ApprovalLabel);
+
+        vm.ToggleApprovalCommand.Execute(null);
+        Assert.Null(exam.ApprovalGrantedAt);
+        Assert.Equal("Genehmigung noch ausstehend", vm.ApprovalLabel);
+    }
+
+    [Fact]
+    public void Selection_ZeigtKorrekturfortschrittOderNotenspiegelJeNachStatus()
+    {
+        var group = new LearningGroup { Name = "Q1 Chemie", SchoolYear = new SchoolYearService().CurrentSchoolYear() };
+        var today = DateOnly.FromDateTime(DateTime.Today);
+        var conducted = new Exam { GroupId = group.Id, Title = "Läuft", Status = ExamStatus.Conducted, Date = today.AddDays(-2) };
+        var returned = new Exam { GroupId = group.Id, Title = "Fertig", Status = ExamStatus.Returned, Date = today.AddDays(-20) };
+        var vm = BuildVm([group], [conducted, returned]);
+        vm.LoadCommand.Execute(null);
+
+        vm.SelectedRow = vm.Rows.Single(r => r.Exam.Id == conducted.Id);
+        Assert.True(vm.ShowCorrectionProgress);
+        Assert.False(vm.ShowGradeSummary);
+
+        vm.SelectedRow = vm.Rows.Single(r => r.Exam.Id == returned.Id);
+        Assert.False(vm.ShowCorrectionProgress);
+        Assert.True(vm.ShowGradeSummary);
+    }
+}

LehrerApp.Desktop.Tests/Fakes.cs

@@ -474,6 +474,56 @@ public class FakeAnnualPlanEvents : IAnnualPlanEventRepository
     public void Delete(Guid id) => _all.RemoveAll(e => e.Id == id);
 }
 
+public class FakeUntisAbsenceCache : IUntisAbsenceCacheRepository
+{
+    private readonly List<UntisAbsenceCacheEntry> _all = [];
+    public List<UntisAbsenceCacheEntry> GetByClassAndRange(string className, int startDate, int endDate) =>
+        _all.Where(e => e.ClassName == className && e.Date >= startDate && e.Date <= endDate).ToList();
+    public void ReplaceRange(string className, int startDate, int endDate, IEnumerable<UntisAbsenceCacheEntry> entries)
+    {
+        _all.RemoveAll(e => e.ClassName == className && e.Date >= startDate && e.Date <= endDate);
+        _all.AddRange(entries);
+    }
+    public void InsertRange(IEnumerable<UntisAbsenceCacheEntry> entries) => _all.AddRange(entries);
+}
+
+public class FakeUntisClassRegisterCache : IUntisClassRegisterCacheRepository
+{
+    private readonly List<UntisClassRegisterCacheEntry> _all = [];
+    public List<UntisClassRegisterCacheEntry> GetByClassAndRange(string className, int startDate, int endDate) =>
+        _all.Where(e => e.ClassName == className && e.Date >= startDate && e.Date <= endDate).ToList();
+    public void ReplaceRange(string className, int startDate, int endDate, IEnumerable<UntisClassRegisterCacheEntry> entries)
+    {
+        _all.RemoveAll(e => e.ClassName == className && e.Date >= startDate && e.Date <= endDate);
+        _all.AddRange(entries);
+    }
+    public void InsertRange(IEnumerable<UntisClassRegisterCacheEntry> entries) => _all.AddRange(entries);
+}
+
+public class FakeUntisStudentRosterCache : IUntisStudentRosterCacheRepository
+{
+    private readonly List<UntisStudentRosterCacheEntry> _all = [];
+    public List<UntisStudentRosterCacheEntry> GetByClass(string className) =>
+        _all.Where(e => e.ClassName == className).ToList();
+    public void ReplaceAll(string className, IEnumerable<UntisStudentRosterCacheEntry> entries)
+    {
+        _all.RemoveAll(e => e.ClassName == className);
+        _all.AddRange(entries);
+    }
+}
+
+public class FakeUntisCacheFetchStates : IUntisCacheFetchStateRepository
+{
+    private readonly List<UntisCacheFetchState> _all = [];
+    public UntisCacheFetchState? Get(string className, UntisCacheKind kind) =>
+        _all.FirstOrDefault(s => s.ClassName == className && s.Kind == kind);
+    public void Save(UntisCacheFetchState state)
+    {
+        _all.RemoveAll(s => s.ClassName == state.ClassName && s.Kind == state.Kind);
+        _all.Add(state);
+    }
+}
+
 public class FakeWorkTasks : IWorkTaskRepository
 {
     private readonly List<WorkTask> _all = [];

LehrerApp.Desktop.Tests/FractionWidthConverterTests.cs

@@ -0,0 +1,37 @@
+using System.Globalization;
+using LehrerApp.Desktop.Converters;
+using Xunit;
+
+namespace LehrerApp.Desktop.Tests;
+
+public sealed class FractionWidthConverterTests
+{
+    [Fact]
+    public void Convert_MultipliziertTrackbreiteMitAnteil()
+    {
+        var result = FractionWidthConverter.Instance.Convert(
+            [200d, 0.25d], typeof(double), null, CultureInfo.InvariantCulture);
+
+        Assert.Equal(50d, result);
+    }
+
+    [Fact]
+    public void Convert_LiefertNullBreiteBeiUngueltigenWerten()
+    {
+        // Bounds.Width kann vor dem ersten Layout-Pass NaN sein (Element noch nicht gemessen) —
+        // darf nicht zu einer negativen oder undefinierten Breite führen.
+        Assert.Equal(0d, FractionWidthConverter.Instance.Convert(
+            [double.NaN, 0.5d], typeof(double), null, CultureInfo.InvariantCulture));
+        Assert.Equal(0d, FractionWidthConverter.Instance.Convert(
+            ["not a double", 0.5d], typeof(double), null, CultureInfo.InvariantCulture));
+    }
+
+    [Fact]
+    public void Convert_ClamptNegativeErgebnisseAufNull()
+    {
+        var result = FractionWidthConverter.Instance.Convert(
+            [100d, -0.2d], typeof(double), null, CultureInfo.InvariantCulture);
+
+        Assert.Equal(0d, result);
+    }
+}

LehrerApp.Desktop.Tests/GlobalSearchViewModelTests.cs

@@ -0,0 +1,74 @@
+using LehrerApp.Core.Models;
+using LehrerApp.Desktop.ViewModels;
+using Xunit;
+
+namespace LehrerApp.Desktop.Tests;
+
+public sealed class GlobalSearchViewModelTests
+{
+    [Fact]
+    public void LeereSuche_ZeigtSchnellaktionen()
+    {
+        var vm = BuildVm();
+
+        Assert.Collection(vm.Results,
+            item => Assert.Equal(GlobalSearchAction.NewTask, item.Action),
+            item => Assert.Equal(GlobalSearchAction.NewReminder, item.Action),
+            item => Assert.Equal(GlobalSearchAction.NewStudent, item.Action));
+        Assert.Same(vm.Results[0], vm.SelectedResult);
+    }
+
+    [Fact]
+    public void Suche_FindetSchuelerGruppeKlausurUndAufgabe()
+    {
+        var group = new LearningGroup { Name = "9 Chemie", SchoolYear = "2026/27", GradeLevel = 9 };
+        var student = new Student { FirstName = "Mia", LastName = "Chemie" };
+        var exam = new Exam { GroupId = group.Id, Title = "Chemie-Test", Date = new DateOnly(2026, 9, 1) };
+        var tasks = new FakeWorkTasks();
+        tasks.Add(new WorkTask { GroupId = group.Id, Title = "Chemie-Klausur korrigieren" });
+        var vm = BuildVm([student], [group], [exam], tasks);
+
+        vm.Query = "Chemie";
+
+        Assert.Contains(vm.Results, x => x.Kind == GlobalSearchResultKind.Student && x.EntityId == student.Id);
+        Assert.Contains(vm.Results, x => x.Kind == GlobalSearchResultKind.Group && x.EntityId == group.Id);
+        Assert.Contains(vm.Results, x => x.Kind == GlobalSearchResultKind.Exam && x.EntityId == exam.Id);
+        Assert.Contains(vm.Results, x => x.Kind == GlobalSearchResultKind.Task && x.Title.Contains("korrigieren"));
+    }
+
+    [Fact]
+    public async Task TrefferAusfuehren_NavigiertUndSchliesstPalette()
+    {
+        var student = new Student { FirstName = "Mia", LastName = "Muster" };
+        var vm = BuildVm([student]);
+        vm.Query = "Muster";
+        var result = Assert.Single(vm.Results, x => x.Kind == GlobalSearchResultKind.Student);
+        GlobalSearchResult? navigated = null;
+        var closed = false;
+        vm.OnNavigate = x => navigated = x;
+        vm.OnClose = () => closed = true;
+
+        await vm.ExecuteCommand.ExecuteAsync(result);
+
+        Assert.Same(result, navigated);
+        Assert.True(closed);
+    }
+
+    [Fact]
+    public async Task ErinnerungSchnellErfassen_StartetDialogAlsErinnerung()
+    {
+        var vm = BuildVm();
+        bool? reminder = null;
+        vm.OnQuickAddTask = value => { reminder = value; return Task.CompletedTask; };
+        var action = vm.Results.Single(x => x.Action == GlobalSearchAction.NewReminder);
+
+        await vm.ExecuteCommand.ExecuteAsync(action);
+
+        Assert.True(reminder);
+    }
+
+    private static GlobalSearchViewModel BuildVm(List<Student>? students = null,
+        List<LearningGroup>? groups = null, List<Exam>? exams = null, FakeWorkTasks? tasks = null) =>
+        new(new FakeStudents(students ?? []), new FakeGroups(groups ?? []),
+            new FakeExams(exams ?? []), tasks ?? new FakeWorkTasks());
+}

LehrerApp.Desktop.Tests/GroupListViewModelTests.cs

@@ -5,76 +5,69 @@ using Xunit;
 
 namespace LehrerApp.Desktop.Tests;
 
-/// Tests für den Schnellüberblick im Auswahl-Panel der Gruppenliste (Nutzer-Feedback:
+/// <summary>Tests für die direkte, einlagige Lerngruppen-Navigation.</summary>
-/// "oberhalb der Buttonliste ein paar Daten auswerfen. Nächste Stunde, nächste Arbeit,
-/// wichtige Todos").
 public sealed class GroupListViewModelTests
 {
-    private static GroupListViewModel BuildVm(LearningGroup group, FakeLessons? lessons = null,
+    private static GroupListViewModel BuildVm(params LearningGroup[] groups) =>
-        FakeExams? exams = null, FakeWorkTasks? tasks = null) =>
+        new(new FakeGroups([.. groups]), new FakeSubjects([]), new SchoolYearService());
-        new(new FakeGroups([group]), new FakeSubjects([]), new SchoolYearService(),
-            lessons ?? new FakeLessons(), exams ?? new FakeExams([]), tasks ?? new FakeWorkTasks());
 
     [Fact]
-    public void SelectedGroup_OhneDatenZeigtKeinenSchnellueberblick()
+    public void Gruppenkarte_OeffnetDirektDieUebersicht()
     {
-        var group = new LearningGroup { Name = "9c" };
+        var group = CurrentGroup("9c");
         var vm = BuildVm(group);
+        Guid? openedId = null;
+        int? openedTab = null;
+        vm.OnNavigateToDetail = (id, tab) => { openedId = id; openedTab = tab; };
 
-        vm.SelectedGroup = vm.Groups.Count > 0 ? vm.Groups[0] : new GroupListItem(group, "");
+        Assert.Single(vm.Groups).OpenCommand.Execute(null);
 
-        Assert.False(vm.QuickHasAnything);
+        Assert.Equal(group.Id, openedId);
+        Assert.Equal(0, openedTab);
     }
 
     [Fact]
-    public void SelectedGroup_ZeigtNaechsteGeplanteStundeUndKlausur()
+    public async Task Verwaltungsmenue_BearbeitetDieGewaehlteKarteOhneZwischenauswahl()
     {
-        var group = new LearningGroup { Name = "9c" };
+        var first = CurrentGroup("9a");
-        var today = DateOnly.FromDateTime(DateTime.Today);
+        var second = CurrentGroup("9b");
-        var lessons = new FakeLessons();
+        var vm = BuildVm(first, second);
-        lessons.Add(new Lesson { GroupId = group.Id, Date = today.AddDays(3), Topic = "Redox", Status = LessonStatus.Planned });
+        Guid? editedId = null;
-        var exams = new FakeExams([new Exam { GroupId = group.Id, Date = today.AddDays(10), Title = "Klausur 1" }]);
+        vm.OnEditGroup = id => { editedId = id; return Task.CompletedTask; };
-        var vm = BuildVm(group, lessons: lessons, exams: exams);
+        var secondItem = vm.Groups.Single(x => x.Id == second.Id);
 
-        vm.SelectedGroup = new GroupListItem(group, "");
+        await secondItem.EditCommand.ExecuteAsync(null);
 
-        Assert.True(vm.QuickHasNextLesson);
+        Assert.Equal(second.Id, editedId);
-        Assert.Contains("Redox", vm.QuickNextLessonLabel);
-        Assert.True(vm.QuickHasNextExam);
-        Assert.Contains("Klausur 1", vm.QuickNextExamLabel);
-        Assert.True(vm.QuickHasAnything);
     }
 
     [Fact]
-    public void SelectedGroup_ZeigtOffeneAufgabenDieserGruppeSortiertNachFaelligkeit()
+    public void Suche_FiltertWeiterhinNachGruppenname()
     {
-        var group = new LearningGroup { Name = "9c" };
+        var vm = BuildVm(CurrentGroup("9 Chemie"), CurrentGroup("10 Mathematik"));
-        var today = DateOnly.FromDateTime(DateTime.Today);
-        var tasks = new FakeWorkTasks();
-        tasks.Add(new WorkTask { GroupId = group.Id, Title = "Bald fällig", DueDate = today.AddDays(1), Status = WorkTaskStatus.Open });
-        tasks.Add(new WorkTask { GroupId = group.Id, Title = "Erledigt", DueDate = today, Status = WorkTaskStatus.Done });
-        tasks.Add(new WorkTask { GroupId = Guid.NewGuid(), Title = "Andere Gruppe", DueDate = today, Status = WorkTaskStatus.Open });
-        var vm = BuildVm(group, tasks: tasks);
 
-        vm.SelectedGroup = new GroupListItem(group, "");
+        vm.SearchText = "Chemie";
 
-        Assert.True(vm.QuickHasTasks);
+        Assert.Equal("9 Chemie", Assert.Single(vm.Groups).Name);
-        Assert.Equal("Bald fällig", Assert.Single(vm.QuickTasks).Title);
     }
 
     [Fact]
-    public void SelectedGroup_Zuruecksetzen_LeertSchnellueberblick()
+    public void Archivieren_WirktAufDieKarteUndEntferntSieAusDerAktivenListe()
     {
-        var group = new LearningGroup { Name = "9c" };
+        var group = CurrentGroup("9c");
-        var today = DateOnly.FromDateTime(DateTime.Today);
+        var vm = BuildVm(group);
-        var exams = new FakeExams([new Exam { GroupId = group.Id, Date = today.AddDays(10), Title = "Klausur 1" }]);
+        var item = Assert.Single(vm.Groups);
-        var vm = BuildVm(group, exams: exams);
-        vm.SelectedGroup = new GroupListItem(group, "");
-        Assert.True(vm.QuickHasAnything);
 
-        vm.SelectedGroup = null;
+        item.ToggleArchiveCommand.Execute(null);
 
-        Assert.False(vm.QuickHasAnything);
+        Assert.False(group.IsActive);
-        Assert.Empty(vm.QuickTasks);
+        Assert.Empty(vm.Groups);
     }
+
+    private static LearningGroup CurrentGroup(string name) => new()
+    {
+        Name = name,
+        SchoolYear = new SchoolYearService().CurrentSchoolYear(),
+        IsActive = true,
+    };
 }

LehrerApp.Desktop.Tests/TeachingModeViewModelTests.cs

@@ -13,6 +13,17 @@ public sealed class TeachingModeViewModelTests
             new FakeStudents(students ?? []), new FakeMemberships(memberships ?? []),
             sessions ?? new FakeSessions([]), new FakeEntries(), new FakeAspects());
 
+    /// Dieselben Fakes wie <see cref="BuildSeatingPlan"/>, aber für ParticipationTabViewModel —
+    /// beide brauchen eigene IParticipationSessionRepository/IParticipationRepository-Instanzen
+    /// im Produktivcode (siehe TeachingModeWindow-Kommentar zu ReloadSeatBadgesFromRepository),
+    /// hier reicht für die Tests aber eine gemeinsame FakeSessions-Instanz, damit beide
+    /// ViewModels dieselbe verknüpfte Sitzung sehen.
+    private static ParticipationTabViewModel BuildParticipation(LearningGroup group,
+        FakeSessions? sessions = null) =>
+        new(sessions ?? new FakeSessions([]), new FakeEntries(), new FakeAspects(),
+            new FakeStudents([]), new FakeMemberships([]), new FakeGroups([group]),
+            new FakeCompetencyDomains());
+
     [Fact]
     public void Konstruktor_LaedtVerlaufsplanUndInitialisiertSitzplanFuerDieGruppe()
     {
@@ -24,7 +35,8 @@ public sealed class TeachingModeViewModelTests
         };
         var seatingPlan = BuildSeatingPlan(group.Id);
 
-        var vm = new TeachingModeViewModel(lesson, group, new FakeAlternativeLessonPaths([]), seatingPlan);
+        var vm = new TeachingModeViewModel(lesson, group, new FakeAlternativeLessonPaths([]),
+            new FakeLessons(), seatingPlan, BuildParticipation(group));
 
         Assert.Equal("Q1 Chemie", vm.GroupName);
         Assert.Equal("Redox", vm.LessonInfo.Topic);
@@ -41,13 +53,37 @@ public sealed class TeachingModeViewModelTests
         var sessions = new FakeSessions([]);
         var seatingPlan = BuildSeatingPlan(group.Id, sessions);
 
-        var vm = new TeachingModeViewModel(lesson, group, new FakeAlternativeLessonPaths([]), seatingPlan);
+        var vm = new TeachingModeViewModel(lesson, group, new FakeAlternativeLessonPaths([]),
+            new FakeLessons(), seatingPlan, BuildParticipation(group, sessions));
 
         var created = Assert.Single(sessions.GetByGroup(group.Id));
         Assert.Equal(lesson.Id, created.LessonId);
         Assert.Equal(vm.SeatingPlan.SelectedSession?.Id, created.Id);
     }
 
+    /// Nutzer-Feedback: Schnellbewertungs-Dialoge (Mitarbeit, Anwesenheit/Hausaufgabe) sollen sich
+    /// im Unterrichtsmodus direkt öffnen lassen — das setzt voraus, dass die dafür verwendete
+    /// ParticipationTabViewModel-Instanz von Anfang an auf der zu dieser Stunde gehörenden
+    /// Sitzung steht, nicht auf einer beliebigen anderen Sitzung der Gruppe.
+    [Fact]
+    public void Konstruktor_SelektiertDieselbeSitzungAuchInDerParticipationViewModel()
+    {
+        var group = new LearningGroup { Name = "Q1 Chemie" };
+        var lesson = new Lesson
+        { GroupId = group.Id, Date = DateOnly.FromDateTime(DateTime.Today), Topic = "Redox" };
+        var otherSession = new ParticipationSession
+        { GroupId = group.Id, Date = lesson.Date.AddDays(-1), Comment = "Andere Stunde" };
+        var sessions = new FakeSessions([otherSession]);
+        var seatingPlan = BuildSeatingPlan(group.Id, sessions);
+
+        var vm = new TeachingModeViewModel(lesson, group, new FakeAlternativeLessonPaths([]),
+            new FakeLessons(), seatingPlan, BuildParticipation(group, sessions));
+
+        Assert.NotNull(vm.SeatingPlan.SelectedSession);
+        Assert.Equal(vm.SeatingPlan.SelectedSession!.Id, vm.Participation.SelectedSession?.Id);
+        Assert.NotEqual(otherSession.Id, vm.Participation.SelectedSession?.Id);
+    }
+
     [Fact]
     public void Konstruktor_BereitsExistierendeVerknuepfteSitzung_WirdWiederverwendet()
     {
@@ -59,7 +95,8 @@ public sealed class TeachingModeViewModelTests
         var sessions = new FakeSessions([existing]);
         var seatingPlan = BuildSeatingPlan(group.Id, sessions);
 
-        var vm = new TeachingModeViewModel(lesson, group, new FakeAlternativeLessonPaths([]), seatingPlan);
+        var vm = new TeachingModeViewModel(lesson, group, new FakeAlternativeLessonPaths([]),
+            new FakeLessons(), seatingPlan, BuildParticipation(group, sessions));
 
         Assert.Single(sessions.GetByGroup(group.Id));
         Assert.Equal(existing.Id, vm.SeatingPlan.SelectedSession?.Id);
@@ -75,8 +112,92 @@ public sealed class TeachingModeViewModelTests
         { GroupId = group.Id, Date = DateOnly.FromDateTime(DateTime.Today), Topic = "Redox" };
         var seatingPlan = BuildSeatingPlan(group.Id);
 
-        var vm = new TeachingModeViewModel(lesson, group, new FakeAlternativeLessonPaths([]), seatingPlan);
+        var vm = new TeachingModeViewModel(lesson, group, new FakeAlternativeLessonPaths([]),
+            new FakeLessons(), seatingPlan, BuildParticipation(group));
 
         Assert.False(vm.SeatingPlan.IsEditable);
     }
+
+    // ── Hausaufgabe: letzte Stunde ansehen/abhaken, aktuelle einsehen/ändern ─────
+
+    [Fact]
+    public void Konstruktor_FindetHausaufgabeDerVorherigenStunde()
+    {
+        var group = new LearningGroup { Name = "Q1 Chemie" };
+        var today = DateOnly.FromDateTime(DateTime.Today);
+        var previous = new Lesson
+        {
+            GroupId = group.Id, Date = today.AddDays(-7), Topic = "Säuren",
+            Homework = "S. 42, Aufgabe 3", HomeworkChecked = false,
+        };
+        var lesson = new Lesson { GroupId = group.Id, Date = today, Topic = "Redox" };
+        var lessons = new FakeLessons();
+        lessons.Add(previous);
+        var seatingPlan = BuildSeatingPlan(group.Id);
+
+        var vm = new TeachingModeViewModel(lesson, group, new FakeAlternativeLessonPaths([]),
+            lessons, seatingPlan, BuildParticipation(group));
+
+        Assert.True(vm.Homework.HasPreviousHomework);
+        Assert.Equal("S. 42, Aufgabe 3", vm.Homework.PreviousHomeworkText);
+        Assert.Contains("Säuren", vm.Homework.PreviousLessonLabel);
+        Assert.False(vm.Homework.PreviousHomeworkChecked);
+    }
+
+    [Fact]
+    public void Konstruktor_IgnoriertVorherigeStundeOhneHausaufgabe()
+    {
+        var group = new LearningGroup { Name = "Q1 Chemie" };
+        var today = DateOnly.FromDateTime(DateTime.Today);
+        var previous = new Lesson { GroupId = group.Id, Date = today.AddDays(-7), Topic = "Säuren" };
+        var lesson = new Lesson { GroupId = group.Id, Date = today, Topic = "Redox" };
+        var lessons = new FakeLessons();
+        lessons.Add(previous);
+        var seatingPlan = BuildSeatingPlan(group.Id);
+
+        var vm = new TeachingModeViewModel(lesson, group, new FakeAlternativeLessonPaths([]),
+            lessons, seatingPlan, BuildParticipation(group));
+
+        Assert.False(vm.Homework.HasPreviousHomework);
+    }
+
+    [Fact]
+    public void PreviousHomeworkChecked_SpeichertSofortAnDerVorherigenStunde()
+    {
+        var group = new LearningGroup { Name = "Q1 Chemie" };
+        var today = DateOnly.FromDateTime(DateTime.Today);
+        var previous = new Lesson
+        { GroupId = group.Id, Date = today.AddDays(-7), Topic = "Säuren", Homework = "S. 42" };
+        var lesson = new Lesson { GroupId = group.Id, Date = today, Topic = "Redox" };
+        var lessons = new FakeLessons();
+        lessons.Add(previous);
+        var seatingPlan = BuildSeatingPlan(group.Id);
+        var vm = new TeachingModeViewModel(lesson, group, new FakeAlternativeLessonPaths([]),
+            lessons, seatingPlan, BuildParticipation(group));
+
+        vm.Homework.PreviousHomeworkChecked = true;
+
+        var saved = Assert.Single(lessons.GetByGroupAndRange(group.Id, today.AddDays(-120), today.AddDays(-1)));
+        Assert.True(saved.HomeworkChecked);
+    }
+
+    [Fact]
+    public void SaveCurrentHomework_SchreibtAufDieAktuelleStunde()
+    {
+        var group = new LearningGroup { Name = "Q1 Chemie" };
+        var lesson = new Lesson
+        { GroupId = group.Id, Date = DateOnly.FromDateTime(DateTime.Today), Topic = "Redox" };
+        var lessons = new FakeLessons();
+        lessons.Add(lesson);
+        var seatingPlan = BuildSeatingPlan(group.Id);
+        var vm = new TeachingModeViewModel(lesson, group, new FakeAlternativeLessonPaths([]),
+            lessons, seatingPlan, BuildParticipation(group));
+
+        vm.Homework.CurrentHomework = "AB 7 fertigstellen";
+        vm.Homework.SaveCurrentHomeworkCommand.Execute(null);
+
+        var saved = Assert.Single(lessons.GetByGroupAndRange(group.Id, lesson.Date, lesson.Date));
+        Assert.Equal("AB 7 fertigstellen", saved.Homework);
+        Assert.Equal("Gespeichert.", vm.Homework.SaveStatus);
+    }
 }

LehrerApp.Desktop.Tests/TimetableViewModelTests.cs

@@ -14,10 +14,11 @@ public sealed class TimetableViewModelTests
         FakeSubjects? subjects = null, FakeLessons? lessons = null, FakeExams? exams = null,
         SchoolCalendarSettingsService? calendarSettings = null,
         FakeSupervisionDuties? supervisionDuties = null, FakeSubstitutionEntries? substitutions = null,
-        FakeUntisSlotMappings? untisMappings = null, WebUntisSettingsService? untisSettings = null)
+        FakeUntisSlotMappings? untisMappings = null, WebUntisSettingsService? untisSettings = null,
+        PeriodScheduleService? periodSchedule = null)
     {
-        // Bewusst kein "using": SchoolCalendarSettingsService liest den Pfad nur bei Bedarf
+        // Bewusst kein "using": SchoolCalendarSettingsService/PeriodScheduleService lesen den Pfad
-        // (SetState), das Verzeichnis muss über die Lebensdauer des ViewModels bestehen bleiben.
+        // nur bei Bedarf, das Verzeichnis muss über die Lebensdauer des ViewModels bestehen bleiben.
         var tempPath = System.IO.Path.Combine(
             System.IO.Path.GetTempPath(), $"lehrerapp-timetablevm-tests-{Guid.NewGuid():N}");
         Directory.CreateDirectory(tempPath);
@@ -28,7 +29,8 @@ public sealed class TimetableViewModelTests
             calendarSettings ?? new SchoolCalendarSettingsService(tempPath),
             new PublicHolidayService(), new SchoolYearService(),
             supervisionDuties ?? new FakeSupervisionDuties(), substitutions ?? new FakeSubstitutionEntries(),
-            untisMappings ?? new FakeUntisSlotMappings(), untisSettings ?? TestSupport.BuildWebUntisSettingsService());
+            untisMappings ?? new FakeUntisSlotMappings(), untisSettings ?? TestSupport.BuildWebUntisSettingsService(),
+            periodSchedule ?? new PeriodScheduleService(tempPath));
     }
 
     /// Nächstes Datum ab (inkl.) <paramref name="from"/>, das auf einen Wochentag Mo-Fr fällt —
@@ -336,6 +338,88 @@ public sealed class TimetableViewModelTests
         Assert.Equal(lesson.Id, openedLesson?.Id);
     }
 
+    /// Nutzer-Feedback (zweite Runde): der Direktklick auf eine Wochenraster-Kachel soll
+    /// "einheitlicher" springen — bei einer Lesson HEUTE, während gerade Unterrichtszeit ist,
+    /// direkt in den Unterrichtsmodus statt in den (schreibgeschützten) Planungsviewer.
+    [Fact]
+    public async Task OpenWeekCell_LessonHeuteWaehrendUnterrichtszeit_OeffnetUnterrichtsmodus()
+    {
+        var group = new LearningGroup { Name = "Q1 Chemie" };
+        // Bewusst nicht der reale DateTime.Today-Wochentag: an einem Sa/So gäbe es dafür keine
+        // Kachel im Mo-Fr-Raster. Stattdessen ein beliebiger Wochentag der laufenden Kalenderwoche
+        // (Kachel existiert immer), dessen Datum per VM.Clock als "heute" simuliert wird (siehe
+        // TimetableViewModel.Clock - genau für solche Tests eingeführt).
+        var weekday = DayOfWeek.Monday;
+        var lessonDate = DateInCurrentWeek(weekday);
+        var slots = new FakeTimetableSlots();
+        slots.Add(new TimetableSlot { GroupId = group.Id, Weekday = weekday, PeriodNumber = 1 });
+        var lesson = new Lesson { GroupId = group.Id, Date = lessonDate, LessonNumber = 1, Topic = "Redox" };
+        var lessons = new FakeLessons();
+        lessons.Add(lesson);
+        var periodSchedule = BuildPeriodSchedule(1);
+        var vm = BuildViewModel(slots, new FakeGroups([group]), lessons: lessons, periodSchedule: periodSchedule);
+        // Gleiche Uhrzeit wie BuildPeriodSchedule (reales DateTime.Now), aber am simulierten
+        // "heutigen" Datum - die Stundenzeit-Prüfung (Uhrzeit) bleibt so unabhängig vom Datum.
+        vm.Clock = () => lessonDate.ToDateTime(TimeOnly.FromDateTime(DateTime.Now));
+        Lesson? teachingModeLesson = null;
+        Lesson? viewerLesson = null;
+        vm.OnOpenTeachingMode = l => { teachingModeLesson = l; return Task.CompletedTask; };
+        vm.OnOpenLessonViewer = l => { viewerLesson = l; return Task.CompletedTask; };
+
+        var cell = vm.WeekItems.Single(c => c.IsSlotCell && c.Weekday == weekday && c.PeriodNumber == 1);
+        await vm.OpenWeekCellCommand.ExecuteAsync(cell);
+
+        Assert.Equal(lesson.Id, teachingModeLesson?.Id);
+        Assert.Null(viewerLesson);
+    }
+
+    /// Dieselbe Stundenzeit passt, die Lesson liegt aber nicht heute — bleibt beim Viewer.
+    [Fact]
+    public async Task OpenWeekCell_LessonNichtHeuteTrotzPassenderUhrzeit_OeffnetViewer()
+    {
+        var group = new LearningGroup { Name = "Q1 Chemie" };
+        var today = DateOnly.FromDateTime(DateTime.Today);
+        var otherWeekday = today.DayOfWeek == DayOfWeek.Monday ? DayOfWeek.Tuesday : DayOfWeek.Monday;
+        var otherDate = DateInCurrentWeek(otherWeekday);
+        var slots = new FakeTimetableSlots();
+        slots.Add(new TimetableSlot { GroupId = group.Id, Weekday = otherWeekday, PeriodNumber = 1 });
+        var lesson = new Lesson { GroupId = group.Id, Date = otherDate, LessonNumber = 1, Topic = "Redox" };
+        var lessons = new FakeLessons();
+        lessons.Add(lesson);
+        var periodSchedule = BuildPeriodSchedule(1);
+        var vm = BuildViewModel(slots, new FakeGroups([group]), lessons: lessons, periodSchedule: periodSchedule);
+        Lesson? teachingModeLesson = null;
+        Lesson? viewerLesson = null;
+        vm.OnOpenTeachingMode = l => { teachingModeLesson = l; return Task.CompletedTask; };
+        vm.OnOpenLessonViewer = l => { viewerLesson = l; return Task.CompletedTask; };
+
+        var cell = vm.WeekItems.Single(c => c.IsSlotCell && c.Weekday == otherWeekday && c.PeriodNumber == 1);
+        await vm.OpenWeekCellCommand.ExecuteAsync(cell);
+
+        Assert.Equal(lesson.Id, viewerLesson?.Id);
+        Assert.Null(teachingModeLesson);
+    }
+
+    /// Weites Zeitfenster um <paramref name="around"/> herum (±2 Stunden), damit der Test nicht an
+    /// die exakte Toleranz von TimetableViewModel.TeachingTimeTolerance gebunden ist.
+    /// Start UND Ende exakt auf "jetzt" statt eines künstlich breiteren Fensters (z.B. ganzer Tag
+    /// via TimeOnly.MinValue/MaxValue): TimetableViewModel.IsAroundTeachingTime addiert selbst
+    /// noch ±10 Minuten Toleranz (TeachingTimeTolerance) auf Start/Ende — ein zusätzliches, vom
+    /// Test vorgegebenes Fenster würde nahe Mitternacht durch die TimeOnly-Arithmetik (wrappt bei
+    /// 24 Uhr) selbst kippen. "Jetzt" als Start/Ende bleibt nur dann riskant, wenn der Test
+    /// zufällig innerhalb der letzten/ersten 10 Minuten des Tages läuft — dasselbe inhärente
+    /// Randproblem hätte dann auch die Produktion, kein Testartefakt.
+    private static PeriodScheduleService BuildPeriodSchedule(int periodNumber)
+    {
+        var tempPath = System.IO.Path.Combine(
+            System.IO.Path.GetTempPath(), $"lehrerapp-periodschedule-tests-{Guid.NewGuid():N}");
+        Directory.CreateDirectory(tempPath);
+        var service = new PeriodScheduleService(tempPath);
+        var now = TimeOnly.FromDateTime(DateTime.Now);
+        service.SetPeriods([new PeriodTimeEntry { PeriodNumber = periodNumber, Start = now, End = now }]);
+        return service;
+    }
+
     [Fact]
     public void OpenSettings_RuftOnNavigateToSettingsAuf()
     {
@@ -1177,3 +1261,43 @@ public sealed class TimetableViewModelTests
         Assert.False(vm.HasUntisMismatch);
     }
 }
+
+/// Nutzer-Feedback (zweite Runde): das Popup-Menü je Wochenraster-Kachel (TimetableView.axaml,
+/// MenuFlyout) blendet "Unterrichtsansicht"/"Planungsviewer" per IsVisible="{Binding HasLesson}"
+/// aus, wenn für den Slot noch keine Lesson existiert, und den ganzen Menü-Trigger per
+/// IsVisible="{Binding HasGroupId}", wenn die Kachel gar keiner Gruppe zugeordnet ist (z.B. eine
+/// GroupId-lose Vertretung). Diese beiden Properties sind die Grundlage dafür.
+public sealed class WeekCellItemMenuVisibilityTests
+{
+    [Fact]
+    public void ForSlot_MitLesson_HatHasLessonUndHasGroupId()
+    {
+        var lesson = new Lesson { Topic = "Redox" };
+        var cell = WeekCellItem.ForSlot(DayOfWeek.Monday, 3, isToday: true, "Che", "Q1 Chemie",
+            "R204", "Redox", "#4C8DFF", "", hasExam: false, isLastBeforeExam: false,
+            hasExperiment: false, Guid.NewGuid(), isHoliday: false, lesson: lesson);
+
+        Assert.True(cell.HasLesson);
+        Assert.True(cell.HasGroupId);
+    }
+
+    [Fact]
+    public void ForSlot_OhneLesson_HatKeinHasLesson()
+    {
+        var cell = WeekCellItem.ForSlot(DayOfWeek.Monday, 3, isToday: true, "Che", "Q1 Chemie",
+            "R204", "", "#4C8DFF", "", hasExam: false, isLastBeforeExam: false,
+            hasExperiment: false, Guid.NewGuid(), isHoliday: false);
+
+        Assert.False(cell.HasLesson);
+        Assert.True(cell.HasGroupId);
+    }
+
+    [Fact]
+    public void ForSubstitutionLesson_OhneGroupId_HatKeinHasGroupId()
+    {
+        var cell = WeekCellItem.ForSubstitutionLesson(DayOfWeek.Monday, 3, isToday: true,
+            new SubstitutionEntry { GroupId = null, GroupLabel = "Fremde Klasse", Description = "Vertretung" });
+
+        Assert.False(cell.HasGroupId);
+    }
+}

LehrerApp.Desktop.Tests/UntisNameMatchingTests.cs

@@ -0,0 +1,21 @@
+using LehrerApp.Desktop.ViewModels.ClassTeacher;
+using Xunit;
+
+namespace LehrerApp.Desktop.Tests;
+
+public sealed class UntisNameMatchingTests
+{
+    [Theory]
+    [InlineData("Ben Schmidt", "Schmidt Ben")]
+    [InlineData("Ada Müller", "MÜLLER ADA")]
+    [InlineData("Max Mustermann", "mustermann   max")]
+    public void NamesMatch_IstReihenfolgeUndGrossKleinschreibungUnabhaengig(string a, string b) =>
+        Assert.True(UntisNameMatching.NamesMatch(a, b));
+
+    [Theory]
+    [InlineData("Ben Schmidt", "Ben Müller")]
+    [InlineData(null, "Ben Schmidt")]
+    [InlineData("Ben Schmidt", "")]
+    public void NamesMatch_LehntUnterschiedlicheOderFehlendeNamenAb(string? a, string b) =>
+        Assert.False(UntisNameMatching.NamesMatch(a, b));
+}

LehrerApp.Desktop.Tests/UntisReportCacheServiceTests.cs

@@ -0,0 +1,208 @@
+using System.Net;
+using System.Text;
+using LehrerApp.Core.Models;
+using LehrerApp.Desktop.Services;
+using Xunit;
+
+namespace LehrerApp.Desktop.Tests;
+
+public sealed class UntisReportCacheServiceTests
+{
+    private static readonly DateOnly Today = new(2026, 8, 25);
+    private static readonly DateOnly HotStart = Today.AddDays(-14);
+
+    // ── Plan(): reine Entscheidungslogik, keine Repositories/HTTP nötig ──────────
+
+    [Fact]
+    public void Plan_ErsterAufruf_LaedtHeissesFensterUndDeckungReichtBisFensteranfang()
+    {
+        var plan = UntisReportCacheService.Plan(null, Today, Today, Today, forceRefresh: false, DateTime.UtcNow);
+
+        Assert.True(plan.RefreshHotWindow);
+        Assert.Equal(HotStart, plan.HotWindowStart);
+        Assert.Equal(Today, plan.HotWindowEnd);
+        Assert.False(plan.FetchColdRange);
+        Assert.Equal(Int(HotStart), plan.ResultingColdCoverageStartDate);
+    }
+
+    [Fact]
+    public void Plan_InnerhalbEinerStunde_KeinErneutesHeissesFenster()
+    {
+        var state = new UntisCacheFetchState
+        {
+            ClassName = "10c", Kind = UntisCacheKind.Absences,
+            HotWindowFetchedAt = DateTime.UtcNow.AddMinutes(-10), ColdCoverageStartDate = Int(HotStart),
+        };
+
+        var plan = UntisReportCacheService.Plan(state, Today, Today, Today, forceRefresh: false, DateTime.UtcNow);
+
+        Assert.False(plan.RefreshHotWindow);
+        Assert.False(plan.FetchColdRange);
+    }
+
+    [Fact]
+    public void Plan_ForceRefresh_LoestTrotzKuerzlichemAbrufAus()
+    {
+        var state = new UntisCacheFetchState
+        {
+            ClassName = "10c", Kind = UntisCacheKind.Absences,
+            HotWindowFetchedAt = DateTime.UtcNow.AddMinutes(-10), ColdCoverageStartDate = Int(HotStart),
+        };
+
+        var plan = UntisReportCacheService.Plan(state, Today, Today, Today, forceRefresh: true, DateTime.UtcNow);
+
+        Assert.True(plan.RefreshHotWindow);
+    }
+
+    [Fact]
+    public void Plan_MehrAlsEineStundeVergangen_FrischtHeissesFensterErneutAuf()
+    {
+        var state = new UntisCacheFetchState
+        {
+            ClassName = "10c", Kind = UntisCacheKind.Absences,
+            HotWindowFetchedAt = DateTime.UtcNow.AddHours(-2), ColdCoverageStartDate = Int(HotStart),
+        };
+
+        var plan = UntisReportCacheService.Plan(state, Today, Today, Today, forceRefresh: false, DateTime.UtcNow);
+
+        Assert.True(plan.RefreshHotWindow);
+    }
+
+    [Fact]
+    public void Plan_AnfrageVorDemHeissenFenster_KeinHeissesFensterAberKalterErstabruf()
+    {
+        var requestStart = HotStart.AddDays(-30);
+        var requestEnd = HotStart.AddDays(-5);
+
+        var plan = UntisReportCacheService.Plan(null, requestStart, requestEnd, Today, forceRefresh: false, DateTime.UtcNow);
+
+        Assert.False(plan.RefreshHotWindow);
+        Assert.True(plan.FetchColdRange);
+        Assert.Equal(requestStart, plan.ColdRangeStart);
+        Assert.Equal(HotStart.AddDays(-1), plan.ColdRangeEnd);
+        Assert.Equal(Int(requestStart), plan.ResultingColdCoverageStartDate);
+    }
+
+    [Fact]
+    public void Plan_BereitsKaltAbgedeckterBereich_KeinAbrufNoetig()
+    {
+        var coveredSince = HotStart.AddDays(-60);
+        var state = new UntisCacheFetchState
+        {
+            ClassName = "10c", Kind = UntisCacheKind.Absences,
+            HotWindowFetchedAt = DateTime.UtcNow, ColdCoverageStartDate = Int(coveredSince),
+        };
+
+        var plan = UntisReportCacheService.Plan(state, coveredSince.AddDays(10), HotStart.AddDays(-20),
+            Today, forceRefresh: false, DateTime.UtcNow);
+
+        Assert.False(plan.RefreshHotWindow);
+        Assert.False(plan.FetchColdRange);
+    }
+
+    [Fact]
+    public void Plan_ErweitertKalteAbdeckungNurBisZumBenoetigtenStart()
+    {
+        var coveredSince = HotStart.AddDays(-30);
+        var earlierStart = HotStart.AddDays(-90);
+        var state = new UntisCacheFetchState
+        {
+            ClassName = "10c", Kind = UntisCacheKind.Absences,
+            HotWindowFetchedAt = DateTime.UtcNow, ColdCoverageStartDate = Int(coveredSince),
+        };
+
+        var plan = UntisReportCacheService.Plan(state, earlierStart, HotStart.AddDays(-40),
+            Today, forceRefresh: false, DateTime.UtcNow);
+
+        Assert.False(plan.RefreshHotWindow);
+        Assert.True(plan.FetchColdRange);
+        Assert.Equal(earlierStart, plan.ColdRangeStart);
+        Assert.Equal(coveredSince.AddDays(-1), plan.ColdRangeEnd);
+        Assert.Equal(Int(earlierStart), plan.ResultingColdCoverageStartDate);
+    }
+
+    private static int Int(DateOnly date) => date.Year * 10000 + date.Month * 100 + date.Day;
+
+    // ── Ende-zu-Ende: erster Aufruf ruft WebUntis ab, zweiter Aufruf binnen einer Stunde nicht ──
+
+    [Fact]
+    public async Task GetClassRegisterEventsAsync_ZweiterAufrufBinnenEinerStunde_RuftWebUntisNichtErneutAb()
+    {
+        var todayLabel = DateTime.Today.ToString("dd.MM.yy");
+        var csv = Encoding.UTF8.GetBytes(
+            "Klasse\tDatum\tFach\tName\tBenutzer\tEintragskategorie\tKategoriegruppe\tText\r\n" +
+            $"10c\t{todayLabel}\tNAT\tMuster Max\tmueller\tMitarb. über Erwart.\tPositiv\tArbeitet gut mit.\r\n");
+        var handler = new QueueHandler(
+            Json("{\"result\":{\"sessionId\":\"s\"}}"),
+            Json("{\"result\":[{\"id\":1,\"name\":\"2026/27\",\"startDate\":20260801,\"endDate\":20270731}]}"),
+            Json("{\"data\":{\"finished\":true,\"error\":false," +
+                 "\"reportParams\":\"get=rpt.tmp&name=ClassregEventPerStudent&format=csv\"}}"),
+            new HttpResponseMessage(HttpStatusCode.OK) { Content = new ByteArrayContent(csv) });
+        var settings = TestSupport.BuildWebUntisSettingsService();
+        await using var untis = new WebUntisIntegrationService(new HttpClient(handler), settings);
+        await untis.ConnectAsync(new WebUntisCredentials("bk-ostvest", "arche.webuntis.com", "lehrkraft", "geheim"));
+
+        var absenceCache = new FakeUntisAbsenceCache();
+        var classRegisterCache = new FakeUntisClassRegisterCache();
+        var rosterCache = new FakeUntisStudentRosterCache();
+        var fetchStates = new FakeUntisCacheFetchStates();
+        var cache = new UntisReportCacheService(untis, absenceCache, classRegisterCache, rosterCache, fetchStates);
+        var today = DateOnly.FromDateTime(DateTime.Today);
+
+        var first = await cache.GetClassRegisterEventsAsync("10c", today, today);
+        Assert.Single(first);
+        Assert.Equal(4, handler.Requests.Count);
+
+        var second = await cache.GetClassRegisterEventsAsync("10c", today, today);
+        Assert.Single(second);
+        Assert.Equal(4, handler.Requests.Count); // keine weiteren Anfragen - aus dem Cache bedient
+    }
+
+    [Fact]
+    public async Task GetStudentRosterAsync_ZweiterAufrufBinnenEinerStunde_RuftWebUntisNichtErneutAb()
+    {
+        var csv = Encoding.UTF8.GetBytes(
+            "id\texternKey\tklasse.name\tname\tlongName\tforeName\r\n" +
+            "1\t9001\t10c\tMUST\tMustermann\tMax\r\n");
+        var handler = new QueueHandler(
+            Json("{\"result\":{\"sessionId\":\"s\"}}"),
+            Json("{\"result\":[{\"id\":1,\"name\":\"2026/27\",\"startDate\":20260801,\"endDate\":20270731}]}"),
+            Json("{\"data\":{\"finished\":true,\"error\":false," +
+                 "\"reportParams\":\"get=rpt.tmp&name=Student&format=csv\"}}"),
+            new HttpResponseMessage(HttpStatusCode.OK) { Content = new ByteArrayContent(csv) });
+        var settings = TestSupport.BuildWebUntisSettingsService();
+        await using var untis = new WebUntisIntegrationService(new HttpClient(handler), settings);
+        await untis.ConnectAsync(new WebUntisCredentials("bk-ostvest", "arche.webuntis.com", "lehrkraft", "geheim"));
+
+        var cache = new UntisReportCacheService(untis, new FakeUntisAbsenceCache(), new FakeUntisClassRegisterCache(),
+            new FakeUntisStudentRosterCache(), new FakeUntisCacheFetchStates());
+
+        var first = await cache.GetStudentRosterAsync("10c");
+        Assert.Single(first);
+        Assert.Equal("Max Mustermann", first[0].DisplayName);
+        Assert.Equal(4, handler.Requests.Count);
+
+        var second = await cache.GetStudentRosterAsync("10c");
+        Assert.Single(second);
+        Assert.Equal(4, handler.Requests.Count); // keine weiteren Anfragen - aus dem Cache bedient
+    }
+
+    private static HttpResponseMessage Json(string json) => new(HttpStatusCode.OK)
+    {
+        Content = new StringContent(json, Encoding.UTF8, "application/json"),
+    };
+
+    private sealed class QueueHandler(params HttpResponseMessage[] responses) : HttpMessageHandler
+    {
+        private readonly Queue<HttpResponseMessage> _responses = new(responses);
+        public List<string> Requests { get; } = [];
+
+        protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request,
+            CancellationToken cancellationToken)
+        {
+            Requests.Add(request.RequestUri?.ToString() ?? "");
+            await Task.Yield();
+            return _responses.Dequeue();
+        }
+    }
+}

LehrerApp.Desktop.Tests/WebUntisIntegrationServiceTests.cs

@@ -0,0 +1,88 @@
+using System.Net;
+using System.Text;
+using LehrerApp.Desktop.Services;
+using Xunit;
+
+namespace LehrerApp.Desktop.Tests;
+
+public sealed class WebUntisIntegrationServiceTests
+{
+    [Fact]
+    public async Task ConnectUndAbruf_GehenDirektAnWebUntisUndVerwendenDieselbeSession()
+    {
+        var handler = new QueueHandler(
+            Json("{\"result\":{\"sessionId\":\"desktop-session\"}}"),
+            Json("{\"result\":[{\"id\":1,\"name\":\"2026/27\",\"startDate\":20260801,\"endDate\":20270731}]}"),
+            Json("{\"result\":[{\"id\":42,\"name\":\"KUE\",\"longName\":\"Kürbis\",\"active\":true}]}"),
+            Json("{\"result\":{}}"));
+        var settings = TestSupport.BuildWebUntisSettingsService();
+        await using var service = new WebUntisIntegrationService(new HttpClient(handler), settings);
+
+        await service.ConnectAsync(new WebUntisCredentials(
+            "bk-ostvest", "arche.webuntis.com", "lehrkraft", "geheim"));
+        var teachers = await service.GetTeachersAsync();
+
+        Assert.Equal("KUE", Assert.Single(teachers).Name);
+        Assert.Equal(3, handler.Requests.Count);
+        Assert.All(handler.Requests, request =>
+            Assert.StartsWith("https://arche.webuntis.com/WebUntis/", request.Uri));
+        Assert.DoesNotContain(handler.Requests, request => request.Uri.Contains("/api/webuntis"));
+        Assert.Single(handler.Requests, request => request.Body.Contains("\"method\":\"authenticate\""));
+    }
+
+    [Fact]
+    public async Task GetClassAbsencesAsync_LoestKlasseNamensbasiertAufUndAdressiertSieAlsKLPlusId()
+    {
+        var csv = Encoding.UTF8.GetBytes(
+            "Schüler*innen\tExterne Id\tText\tKlasse\tDatum\tWochentag\tFehlstd.\tFehlmin.\tLehrkraft\tFach\t" +
+            "Abwesenheitsgrund\tText\tENr\tErledigt\tAbwesenheit zählt\tEntschuldigungstext\tStundennr.\tStatus\tFehltage\r\n" +
+            "Muster Max\t12345\t\t10c\t24.08.26\tMo.\t1\t45\tHED\tChe\tAbsent\tKrank gemeldet\t555\t24.08.26\ttrue\t\t3\tnicht entsch.\t1\r\n");
+        var handler = new QueueHandler(
+            Json("{\"result\":{\"sessionId\":\"desktop-session\"}}"), // authenticate (ConnectAsync)
+            Json("{\"result\":[{\"id\":7,\"name\":\"2026/27\",\"startDate\":20260801,\"endDate\":20270731}]}"), // getSchoolyears (ConnectAsync-Validierung)
+            Json("{\"result\":[{\"id\":7,\"name\":\"2026/27\",\"startDate\":20260801,\"endDate\":20270731}]}"), // getSchoolyears (ResolveClassIdAsync)
+            Json("{\"result\":[{\"id\":874,\"name\":\"10c\"}]}"), // getKlassen
+            Json("{\"data\":{\"finished\":true,\"error\":false," +
+                 "\"reportParams\":\"get=rpt.tmp&name=AbsencePerStudent&format=csv\"}}"),
+            new HttpResponseMessage(HttpStatusCode.OK) { Content = new ByteArrayContent(csv) },
+            Json("{\"result\":{}}")); // logout (Dispose)
+        var settings = TestSupport.BuildWebUntisSettingsService();
+        await using var service = new WebUntisIntegrationService(new HttpClient(handler), settings);
+
+        await service.ConnectAsync(new WebUntisCredentials(
+            "bk-ostvest", "arche.webuntis.com", "lehrkraft", "geheim"));
+        var entries = await service.GetClassAbsencesAsync("10c",
+            new DateOnly(2026, 8, 24), new DateOnly(2026, 8, 28));
+
+        var entry = Assert.Single(entries);
+        Assert.Equal("Muster Max", entry.StudentName);
+        Assert.Equal("nicht entsch.", entry.Status);
+        // Zweimal getSchoolyears: einmal als ConnectAsync-Validierung, einmal in ResolveClassIdAsync.
+        Assert.Equal(2, handler.Requests.Count(request => request.Body.Contains("\"method\":\"getSchoolyears\"")));
+        Assert.Single(handler.Requests, request => request.Body.Contains("\"method\":\"getKlassen\""));
+        Assert.Single(handler.Requests, request =>
+            request.Uri.Contains("reports.do?name=AbsencePerStudent") &&
+            request.Uri.Contains("klasseOrStudentgroupId=KL874"));
+    }
+
+    private static HttpResponseMessage Json(string json) => new(HttpStatusCode.OK)
+    {
+        Content = new StringContent(json, Encoding.UTF8, "application/json"),
+    };
+
+    private sealed class QueueHandler(params HttpResponseMessage[] responses) : HttpMessageHandler
+    {
+        private readonly Queue<HttpResponseMessage> _responses = new(responses);
+        public List<CapturedRequest> Requests { get; } = [];
+
+        protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request,
+            CancellationToken cancellationToken)
+        {
+            Requests.Add(new(request.RequestUri?.ToString() ?? "",
+                request.Content is null ? "" : await request.Content.ReadAsStringAsync(cancellationToken)));
+            return _responses.Dequeue();
+        }
+    }
+
+    private sealed record CapturedRequest(string Uri, string Body);
+}

LehrerApp.Desktop.Tests/WebUntisSettingsServiceTests.cs

@@ -86,4 +86,39 @@ public sealed class WebUntisSettingsServiceTests
         Assert.Equal(at, reloaded.LastSyncAt);
         Assert.Equal("3 Vertretungen erkannt", reloaded.LastSyncStatus);
     }
+
+    [Fact]
+    public void ApiCredentials_SindVerschluesseltUndPersistieren()
+    {
+        var path = BuildTempPath();
+        var credentials = new WebUntisCredentials("schule", "mese.webuntis.com", "lehrkraft", "sehr geheim");
+        var service = new WebUntisSettingsService(path);
+
+        service.SetApiCredentials(credentials);
+        service.SetTeacherUntisId(4711);
+
+        var raw = File.ReadAllText(Path.Combine(path, "webuntis-settings.json"));
+        var reloaded = new WebUntisSettingsService(path);
+        Assert.DoesNotContain("sehr geheim", raw);
+        Assert.True(reloaded.ApiIsConfigured);
+        Assert.Equal(credentials, reloaded.GetApiCredentials());
+        Assert.Equal(4711, reloaded.TeacherUntisId);
+    }
+
+    [Fact]
+    public void ClearApiCredentials_LaesstIcalKonfigurationUnveraendert()
+    {
+        var service = new WebUntisSettingsService(BuildTempPath());
+        service.SetIcalUrl(SampleUrl);
+        service.SetApiCredentials(new("schule", "", "user", "password"));
+        service.SetTeacherUntisId(12);
+
+        service.ClearApiCredentials();
+
+        Assert.False(service.ApiIsConfigured);
+        Assert.Null(service.GetApiCredentials());
+        Assert.Null(service.TeacherUntisId);
+        Assert.True(service.IsConfigured);
+        Assert.Equal(SampleUrl, service.GetIcalUrl());
+    }
 }

LehrerApp.Desktop/App.axaml

@@ -2,6 +2,14 @@
              xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
              x:Class="LehrerApp.Desktop.App"
              RequestedThemeVariant="Default">
+  <Application.Resources>
+    <ResourceDictionary>
+      <ResourceDictionary.MergedDictionaries>
+        <ResourceInclude Source="avares://LehrerApp.Desktop/Styles/SemanticBrushes.axaml"/>
+      </ResourceDictionary.MergedDictionaries>
+    </ResourceDictionary>
+  </Application.Resources>
+
   <Application.Styles>
     <FluentTheme />
     <StyleInclude Source="avares://Avalonia.Controls.DataGrid/Themes/Fluent.xaml"/>

LehrerApp.Desktop/App.axaml.cs

@@ -10,7 +10,9 @@ using LehrerApp.Desktop.ViewModels;
 using LehrerApp.Desktop.ViewModels.Groups;
 using LehrerApp.Desktop.ViewModels.Planning;
 using LehrerApp.Desktop.ViewModels.Students;
+using LehrerApp.Desktop.ViewModels.Workload;
 using LehrerApp.Desktop.Views;
+using LehrerApp.Desktop.Views.Workload;
 using LehrerApp.Sync;
 using Microsoft.Extensions.DependencyInjection;
 
@@ -79,6 +81,15 @@ public class App : Application
 
         var mainVm = Services.GetRequiredService<MainWindowViewModel>();
         WireCallbacks(mainVm);
+
+        // DI-Singletons werden erst beim ersten Auflösen erzeugt. Ohne dieses explizite
+        // Auflösen entstand der Timer des optionalen WebUntis-Abgleichs erst, wenn die
+        // Einstellungen geöffnet oder ein manueller Abruf gestartet wurde. Den Dienst beim
+        // Anwendungsstart aktivieren und wie den Jahresplan sofort einmal abgleichen; danach
+        // übernimmt sein stündlicher Timer.
+        if (Services.GetService<UntisSyncService>() is { } untisSync)
+            _ = untisSync.PollAsync();
+
         var main = new MainWindow { DataContext = mainVm };
         main.EnableWindowSizePersistence(Services.GetRequiredService<WindowSettingsService>());
         if (Services.GetService<SyncEngine>() is { } syncEngine)
@@ -100,11 +111,12 @@ public class App : Application
 
     private static void DisposeServices()
     {
-        if (_serviceProvider is null) return;
+        var serviceProvider = Interlocked.Exchange(ref _serviceProvider, null);
+        if (serviceProvider is null) return;
 
         try
         {
-            _serviceProvider.GetService<LiteDbContext>()?.Checkpoint();
+            serviceProvider.GetService<LiteDbContext>()?.Checkpoint();
         }
         catch (Exception ex)
         {
@@ -112,8 +124,19 @@ public class App : Application
         }
         finally
         {
-            _serviceProvider.Dispose();
+            // Der Exit-Handler läuft synchron auf dem Avalonia-UI-Thread. Die asynchrone
-            _serviceProvider = null;
+            // Entsorgung darf dort nicht mit GetResult() gestartet werden: Fortsetzungen aus
+            // WebUntis/HttpClient könnten sonst auf den blockierten UI-Kontext zurückwarten.
+            try
+            {
+                Task.Run(async () =>
+                    await serviceProvider.DisposeAsync().ConfigureAwait(false))
+                    .GetAwaiter().GetResult();
+            }
+            catch (Exception ex)
+            {
+                AppBootstrapper.Logger.Error("Dienste konnten beim Beenden nicht vollständig freigegeben werden.", ex);
+            }
         }
     }
 
@@ -131,6 +154,23 @@ public class App : Application
         dash.OnNavigateToExam    = id => main.NavigateToGroupDetail(id, 4); // Tab "Klausuren"
         dash.OnNavigateToUnplannedLesson = id => main.NavigateToGroupDetail(id, 6); // Tab "Planung"
 
+        // Globale Suche/Schnellerfassung (14.2): Navigation bleibt im MainWindow-VM, die
+        // vorhandenen Dialog-Helfer übernehmen Eingabe und Validierung.
+        var search = Services.GetRequiredService<GlobalSearchViewModel>();
+        search.OnNavigate = result =>
+        {
+            if (result.Kind == GlobalSearchResultKind.Student && result.EntityId is { } studentId)
+                main.NavigateToStudent(studentId);
+            else if (result.Kind == GlobalSearchResultKind.Group && result.GroupId is { } groupId)
+                main.NavigateToGroupDetail(groupId);
+            else if (result.Kind == GlobalSearchResultKind.Exam && result.GroupId is { } examGroupId)
+                main.NavigateToGroupDetail(examGroupId, 4);
+            else if (result.Kind == GlobalSearchResultKind.Task)
+                main.NavigateToWorkload();
+        };
+        search.OnQuickAddTask = startAsReminder => ShowQuickTaskDialog(startAsReminder, dash);
+        search.OnQuickAddStudent = ShowAddStudentDialog;
+
         // StudentList → StudentDetail + Anlegen
         var sl = Services.GetRequiredService<StudentListViewModel>();
         sl.OnNavigateToDetail = id => main.NavigateToStudent(id);
@@ -150,4 +190,17 @@ public class App : Application
         if (Application.Current?.ApplicationLifetime is IClassicDesktopStyleApplicationLifetime { MainWindow: { } owner })
             await dialog.ShowDialog<bool>(owner);
     }
+
+    private static async Task ShowQuickTaskDialog(bool startAsReminder, DashboardViewModel dashboard)
+    {
+        if (Application.Current?.ApplicationLifetime is not IClassicDesktopStyleApplicationLifetime
+            { MainWindow: { } owner }) return;
+
+        var result = await WorkTaskDialogHelper.ShowDialog(owner, startAsReminder: startAsReminder);
+        if (result is null) return;
+
+        Services.GetRequiredService<IWorkTaskRepository>().Save(result);
+        dashboard.RefreshCommand.Execute(null);
+        Services.GetRequiredService<WorkTaskListViewModel>().Load();
+    }
 }

LehrerApp.Desktop/AppBootstrapper.cs

@@ -5,6 +5,8 @@ using LehrerApp.Data;
 using LehrerApp.Data.Repositories;
 using LehrerApp.Desktop.Services;
 using LehrerApp.Desktop.ViewModels;
+using LehrerApp.Desktop.ViewModels.ClassTeacher;
+using LehrerApp.Desktop.ViewModels.Exams;
 using LehrerApp.Desktop.ViewModels.Groups;
 using LehrerApp.Desktop.ViewModels.Planning;
 using LehrerApp.Desktop.ViewModels.Settings;
@@ -168,6 +170,10 @@ public static class AppBootstrapper
         services.AddSingleton<IUntisSnapshotRepository, UntisSnapshotRepository>();
         services.AddSingleton<IUntisSlotMappingRepository, UntisSlotMappingRepository>();
         services.AddSingleton<IAnnualPlanEventRepository, AnnualPlanEventRepository>();
+        services.AddSingleton<IUntisAbsenceCacheRepository, UntisAbsenceCacheRepository>();
+        services.AddSingleton<IUntisClassRegisterCacheRepository, UntisClassRegisterCacheRepository>();
+        services.AddSingleton<IUntisCacheFetchStateRepository, UntisCacheFetchStateRepository>();
+        services.AddSingleton<IUntisStudentRosterCacheRepository, UntisStudentRosterCacheRepository>();
 
         // ── Services ──────────────────────────────────────────────────────────
         services.AddSingleton<GradingService>();
@@ -223,6 +229,8 @@ public static class AppBootstrapper
         services.AddSingleton(syncSettings);
         services.AddSingleton(_ => new SyncAuthService(new HttpClient()));
         services.AddSingleton(sp => new SchoolWeatherService(new HttpClient(), syncSettings));
+        services.AddSingleton(sp => new WebUntisIntegrationService(new HttpClient(), untisSettings));
+        services.AddSingleton<UntisReportCacheService>();
         // War dieses Gerät schon eingeloggt, aber sync.key fehlt(e), wurde gerade eben (unten)
         // stillschweigend ein neuer, unabhängiger Schlüssel erzeugt - bisher unter dem ALTEN
         // Schlüssel synchronisierte Server-Daten sind für dieses Gerät dann nicht mehr lesbar.
@@ -284,6 +292,7 @@ public static class AppBootstrapper
         // Singleton: einmal erstellt, überall dieselbe Instanz
         services.AddSingleton<AppLockViewModel>();
         services.AddSingleton<MainWindowViewModel>();
+        services.AddSingleton<GlobalSearchViewModel>();
         services.AddSingleton<DashboardViewModel>();
         services.AddSingleton(sp =>
             new SyncStatusViewModel(
@@ -296,6 +305,9 @@ public static class AppBootstrapper
         services.AddSingleton<TimeTrackingViewModel>();
         services.AddSingleton<WorkloadEvaluationViewModel>();
         services.AddSingleton<WorkloadViewModel>();
+        services.AddSingleton<ClassTeacherDetailsViewModel>();
+        services.AddSingleton<ClassTeacherOverviewViewModel>();
+        services.AddSingleton<ExamsOverviewViewModel>();
 
         // Transient: neue Instanz pro Navigation (für Detailseiten)
         services.AddTransient<GroupDetailViewModel>();

LehrerApp.Desktop/Converters/FractionWidthConverter.cs

@@ -0,0 +1,24 @@
+using System.Collections.Generic;
+using System.Globalization;
+using Avalonia.Data.Converters;
+
+namespace LehrerApp.Desktop.Converters;
+
+/// <summary>Multipliziert die gerenderte Breite eines Referenzelements (typischerweise die neutrale
+/// Track-Leiste eines gestapelten Balkens) mit einem Anteil 0…1. Ersetzt eine im ViewModel hart
+/// codierte Pixelkonstante (Quick-Win, Nutzer-Feedback) — die Segmentbreite bleibt damit auch
+/// korrekt, wenn sich die Breite der Seitenspalte in XAML mal ändert, weil sie sich aus der
+/// tatsächlichen <c>Bounds.Width</c> des Track-Elements ergibt statt aus einer angenommenen
+/// festen Breite. `Grid.ColumnDefinitions` ließ sich dafür nicht binden (Avalonia bietet dort bei
+/// kompilierten Bindings keinen Setter — <c>AVLN3000</c>), deshalb MultiBinding auf Pixelbreite
+/// statt Grid-Sternspalten.</summary>
+public sealed class FractionWidthConverter : IMultiValueConverter
+{
+    public static readonly FractionWidthConverter Instance = new();
+
+    public object? Convert(IList<object?> values, Type targetType, object? parameter, CultureInfo culture)
+    {
+        if (values is not [double trackWidth, double fraction, ..] || double.IsNaN(trackWidth)) return 0d;
+        return Math.Max(0d, trackWidth * fraction);
+    }
+}

LehrerApp.Desktop/LehrerApp.Desktop.csproj

@@ -9,6 +9,7 @@
     <ProjectReference Include="..\LehrerApp.Core\LehrerApp.Core.csproj" />
     <ProjectReference Include="..\LehrerApp.Data\LehrerApp.Data.csproj" />
     <ProjectReference Include="..\LehrerApp.Sync\LehrerApp.Sync.csproj" />
+    <ProjectReference Include="..\LehrerApp.WebUntis\LehrerApp.WebUntis.csproj" />
   </ItemGroup>
   <ItemGroup>
     <PackageReference Include="Avalonia" />

LehrerApp.Desktop/Services/UntisReportCacheService.cs

@@ -0,0 +1,171 @@
+using LehrerApp.Core.Interfaces;
+using LehrerApp.Core.Models;
+
+namespace LehrerApp.Desktop.Services;
+
+/// <summary>Ergebnis von <see cref="UntisReportCacheService.Plan"/>: was für eine Anfrage
+/// [<c>RequestStart</c>..<c>RequestEnd</c>, nicht Teil dieses Records, siehe Aufrufer] tatsächlich
+/// live nachgeladen werden muss, und welcher Deckungsstand danach gilt. Bewusst als reine, ohne
+/// Repository/HTTP-Zugriff testbare Funktion ausgelagert (gleiches Muster wie
+/// <see cref="ClassTeacher.ClassAbsenceDaySummaryRow.GroupByStudentAndDay"/>).</summary>
+public readonly record struct UntisCacheRefreshPlan(
+    bool RefreshHotWindow, DateOnly HotWindowStart, DateOnly HotWindowEnd,
+    bool FetchColdRange, DateOnly ColdRangeStart, DateOnly ColdRangeEnd,
+    int? ResultingColdCoverageStartDate);
+
+/// <summary>
+/// Lokaler Cache für die beiden Klassenlehrer-Berichte (Fehlzeiten, Klassenbucheinträge anderer
+/// Lehrkräfte, siehe TODO.md) - Nutzer-Feedback: Warnungen sollen sofort da sein, ohne bei jedem
+/// Öffnen der Ansicht neu abzurufen, und der Bericht darf nicht mehrfach pro Stunde abgerufen
+/// werden (Sorge, bei WebUntis aufzufallen, wenn dieselbe Ansicht mehrfach geöffnet wird). Ein
+/// festes "heißes" Fenster der letzten <see cref="HotWindowDays"/> Tage wird höchstens stündlich
+/// aufgefrischt (dort kann sich der Status noch ändern, z. B. "ausstehend" → "entschuldigt");
+/// alles Ältere gilt als endgültig und wird, einmal abgerufen, dauerhaft aus dem Cache bedient.
+/// Die Cache-Tabellen selbst sind bewusst nicht synchronisiert (siehe
+/// <see cref="IUntisAbsenceCacheRepository"/>-Implementierung) - jedes Gerät füllt seinen Cache
+/// über diesen Service selbst.
+/// </summary>
+public sealed class UntisReportCacheService(
+    WebUntisIntegrationService untis,
+    IUntisAbsenceCacheRepository absenceCache,
+    IUntisClassRegisterCacheRepository classRegisterCache,
+    IUntisStudentRosterCacheRepository rosterCache,
+    IUntisCacheFetchStateRepository fetchState)
+{
+    private static readonly TimeSpan HotWindowRefreshInterval = TimeSpan.FromHours(1);
+    private const int HotWindowDays = 14;
+
+    /// Roster hat anders als Fehlzeiten/Klassenbuch keine Historie (nur "aktueller Stand einer
+    /// Klasse") - deshalb ohne heißes/kaltes Fenster, nur "gilt der letzte Abruf noch als frisch".
+    /// Behebt, dass die Klassenlehrer-Übersicht bei jedem Öffnen spürbar verzögert wirkte: der
+    /// Roster-Abruf lief bislang komplett am Cache vorbei live gegen WebUntis (Nutzer-Feedback).
+    public async Task<IReadOnlyList<UntisStudentRosterCacheEntry>> GetStudentRosterAsync(string className,
+        bool forceRefresh = false, CancellationToken token = default)
+    {
+        var state = fetchState.Get(className, UntisCacheKind.Roster);
+        if (NeedsRefresh(state, forceRefresh, DateTime.UtcNow))
+        {
+            var fresh = await untis.GetStudentsAsync(className, token);
+            rosterCache.ReplaceAll(className, fresh.Students.Select(s => new UntisStudentRosterCacheEntry
+            {
+                ClassName = className, ExternKey = s.ExternKey, DisplayName = s.DisplayName,
+            }));
+            fetchState.Save(new UntisCacheFetchState
+            {
+                Id = state?.Id ?? Guid.NewGuid(), ClassName = className, Kind = UntisCacheKind.Roster,
+                HotWindowFetchedAt = DateTime.UtcNow,
+            });
+        }
+        return rosterCache.GetByClass(className);
+    }
+
+    private static bool NeedsRefresh(UntisCacheFetchState? state, bool forceRefresh, DateTime utcNow) =>
+        forceRefresh || state?.HotWindowFetchedAt is null || utcNow - state.HotWindowFetchedAt >= HotWindowRefreshInterval;
+
+    public async Task<IReadOnlyList<UntisClassAbsenceEntryDto>> GetAbsencesAsync(string className,
+        DateOnly start, DateOnly end, bool forceRefresh = false, CancellationToken token = default)
+    {
+        var state = fetchState.Get(className, UntisCacheKind.Absences);
+        var plan = Plan(state, start, end, Today(), forceRefresh, DateTime.UtcNow);
+
+        if (plan.RefreshHotWindow)
+        {
+            var fresh = await untis.GetClassAbsencesAsync(className, plan.HotWindowStart, plan.HotWindowEnd, token);
+            absenceCache.ReplaceRange(className, Int(plan.HotWindowStart), Int(plan.HotWindowEnd), fresh.Select(ToEntry));
+        }
+        if (plan.FetchColdRange)
+        {
+            var older = await untis.GetClassAbsencesAsync(className, plan.ColdRangeStart, plan.ColdRangeEnd, token);
+            absenceCache.InsertRange(older.Select(ToEntry));
+        }
+        if (plan.RefreshHotWindow || plan.FetchColdRange)
+            fetchState.Save(NextState(state, className, UntisCacheKind.Absences, plan));
+
+        return absenceCache.GetByClassAndRange(className, Int(start), Int(end)).Select(ToDto).ToList();
+    }
+
+    public async Task<IReadOnlyList<UntisForeignClassRegisterEventDto>> GetClassRegisterEventsAsync(
+        string className, DateOnly start, DateOnly end, bool forceRefresh = false, CancellationToken token = default)
+    {
+        var state = fetchState.Get(className, UntisCacheKind.ClassRegister);
+        var plan = Plan(state, start, end, Today(), forceRefresh, DateTime.UtcNow);
+
+        if (plan.RefreshHotWindow)
+        {
+            var fresh = await untis.GetForeignClassRegisterEventsAsync(className, plan.HotWindowStart, plan.HotWindowEnd, token);
+            classRegisterCache.ReplaceRange(className, Int(plan.HotWindowStart), Int(plan.HotWindowEnd), fresh.Select(ToEntry));
+        }
+        if (plan.FetchColdRange)
+        {
+            var older = await untis.GetForeignClassRegisterEventsAsync(className, plan.ColdRangeStart, plan.ColdRangeEnd, token);
+            classRegisterCache.InsertRange(older.Select(ToEntry));
+        }
+        if (plan.RefreshHotWindow || plan.FetchColdRange)
+            fetchState.Save(NextState(state, className, UntisCacheKind.ClassRegister, plan));
+
+        return classRegisterCache.GetByClassAndRange(className, Int(start), Int(end)).Select(ToDto).ToList();
+    }
+
+    /// Reine Entscheidungslogik ohne Repository-/HTTP-Zugriff: was muss für eine Anfrage
+    /// [<paramref name="requestStart"/>..<paramref name="requestEnd"/>] live nachgeladen werden,
+    /// gegeben den zuletzt gespeicherten Zustand. Das heiße Fenster ist immer fest
+    /// [<paramref name="today"/> − <see cref="HotWindowDays"/>, <paramref name="today"/>], unabhängig
+    /// von der angefragten Spanne. Nach einem heißen Refresh reicht die bekannte Abdeckung mindestens
+    /// bis zum Fensteranfang zurück; ein zusätzlicher kalter Abruf erweitert sie nur so weit wie
+    /// für <paramref name="requestStart"/> nötig, nie weiter.
+    public static UntisCacheRefreshPlan Plan(UntisCacheFetchState? state, DateOnly requestStart, DateOnly requestEnd,
+        DateOnly today, bool forceRefresh, DateTime utcNow)
+    {
+        var hotStart = today.AddDays(-HotWindowDays);
+        var refreshHot = requestEnd >= hotStart && (forceRefresh || state?.HotWindowFetchedAt is null
+            || utcNow - state.HotWindowFetchedAt >= HotWindowRefreshInterval);
+
+        int? coverageStart = state?.ColdCoverageStartDate;
+        if (refreshHot)
+            coverageStart = coverageStart is { } existing ? Math.Min(existing, Int(hotStart)) : Int(hotStart);
+
+        var coldEnd = coverageStart is { } covered ? FromInt(covered).AddDays(-1) : hotStart.AddDays(-1);
+        var fetchCold = (coverageStart is null || requestStart < FromInt(coverageStart.Value)) && requestStart <= coldEnd;
+        if (fetchCold) coverageStart = Int(requestStart);
+
+        return new UntisCacheRefreshPlan(refreshHot, hotStart, today, fetchCold, requestStart, coldEnd, coverageStart);
+    }
+
+    private static UntisCacheFetchState NextState(UntisCacheFetchState? previous, string className,
+        UntisCacheKind kind, UntisCacheRefreshPlan plan) => new()
+    {
+        Id = previous?.Id ?? Guid.NewGuid(),
+        ClassName = className,
+        Kind = kind,
+        HotWindowFetchedAt = plan.RefreshHotWindow ? DateTime.UtcNow : previous?.HotWindowFetchedAt,
+        ColdCoverageStartDate = plan.ResultingColdCoverageStartDate,
+    };
+
+    private static DateOnly Today() => DateOnly.FromDateTime(DateTime.Today);
+    private static int Int(DateOnly date) => date.Year * 10000 + date.Month * 100 + date.Day;
+    private static DateOnly FromInt(int value) => new(value / 10000, value / 100 % 100, value % 100);
+
+    private static UntisAbsenceCacheEntry ToEntry(UntisClassAbsenceEntryDto x) => new()
+    {
+        ClassName = x.ClassName, StudentName = x.StudentName, ExternKey = x.ExternKey, Date = x.Date,
+        AbsentPeriods = x.AbsentPeriods, AbsentMinutes = x.AbsentMinutes, TeacherUsernames = x.TeacherUsernames,
+        Subject = x.Subject, AbsenceReason = x.AbsenceReason, Note = x.Note, EntryId = x.EntryId,
+        HandledOn = x.HandledOn, Counts = x.Counts, ExcuseNote = x.ExcuseNote, PeriodNumber = x.PeriodNumber,
+        Status = x.Status, CountsAsFullDay = x.CountsAsFullDay,
+    };
+
+    private static UntisClassAbsenceEntryDto ToDto(UntisAbsenceCacheEntry e) => new(
+        e.StudentName, e.ExternKey, e.ClassName, e.Date, e.AbsentPeriods, e.AbsentMinutes, e.TeacherUsernames,
+        e.Subject, e.AbsenceReason, e.Note, e.EntryId, e.HandledOn, e.Counts, e.ExcuseNote, e.PeriodNumber,
+        e.Status, e.CountsAsFullDay);
+
+    private static UntisClassRegisterCacheEntry ToEntry(UntisForeignClassRegisterEventDto x) => new()
+    {
+        ClassName = x.ClassName, Date = x.Date, Subject = x.Subject, StudentName = x.StudentName,
+        TeacherUsername = x.TeacherUsername, CategoryName = x.CategoryName, CategoryGroup = x.CategoryGroup,
+        Text = x.Text,
+    };
+
+    private static UntisForeignClassRegisterEventDto ToDto(UntisClassRegisterCacheEntry e) => new(
+        e.ClassName, e.Date, e.Subject, e.StudentName, e.TeacherUsername, e.CategoryName, e.CategoryGroup, e.Text);
+}

LehrerApp.Desktop/Services/WebUntisIntegrationService.cs

@@ -0,0 +1,238 @@
+using LehrerApp.WebUntis;
+
+namespace LehrerApp.Desktop.Services;
+
+public sealed class WebUntisIntegrationException(string message) : Exception(message);
+
+public sealed record UntisSchoolYearDto(int UntisId, string Name, int StartDate, int EndDate);
+public sealed record UntisClassDto(int UntisId, string Name, string? LongName);
+public sealed record UntisTeacherDto(int UntisId, string Name, string? ForeName, string? LongName, string? Title,
+    bool Active, IReadOnlyList<int> DepartmentUntisIds)
+{
+    public string DisplayName => string.IsNullOrWhiteSpace(LongName)
+        ? Name
+        : $"{ForeName} {LongName} ({Name})".Trim();
+}
+public sealed record UntisEntityDto(int Id, string Name, int? OriginalId, string? OriginalName, string? ExternalKey);
+public sealed record UntisTimeUnitDto(string Name, int StartTime, int EndTime);
+public sealed record UntisTimeGridDayDto(int Day, IReadOnlyList<UntisTimeUnitDto> TimeUnits);
+public sealed record UntisTimetablePeriodDto(int Id, int Date, int StartTime, int EndTime, string? Code,
+    string? ActivityType, string? Info, string? LessonText, string? SubstitutionText, string? StudentGroup,
+    IReadOnlyList<UntisEntityDto> Classes, IReadOnlyList<UntisEntityDto> Teachers,
+    IReadOnlyList<UntisEntityDto> Subjects, IReadOnlyList<UntisEntityDto> Rooms);
+public sealed record UntisStudentAddressDto(string? Email, string? Mobile, string? Phone, string? City,
+    string? PostCode, string? Street);
+public sealed record UntisStudentDto(int UntisId, int? ExternKey, string ClassName, string? Name, string? LongName,
+    string? ForeName, string DisplayName, string? Gender, int? BirthDate, string? BirthDateRaw, int? EntryDate,
+    string? EntryDateRaw, int? ExitDate, string? ExitDateRaw, string? Text, string? MedicalReportDuty,
+    string? Schulpflicht, string? Majority, UntisStudentAddressDto Address, string? AttributeIL);
+public sealed record UntisStudentReportDto(int Count, string? ClassNameFilter, IReadOnlyList<UntisStudentDto> Students);
+public sealed record UntisLessonAbsenceDto(string StudentName, int Date, int AbsentPeriods,
+    int UnexcusedAbsentPeriods, int AbsentMinutes, int UnexcusedAbsentMinutes, int? StartTime, int? EndTime,
+    string? Reason, int? ExternKey, bool ExternKeyInParentheses, string? HandledOn, bool Counts);
+public sealed record UntisClassRegisterEventDto(string ClassName, int Date, string? Subject,
+    string StudentName, string? CategoryName, string? CategoryGroup, string? Text);
+public sealed record UntisForeignClassRegisterEventDto(string ClassName, int Date, string? Subject,
+    string StudentName, string? TeacherUsername, string? CategoryName, string? CategoryGroup, string? Text);
+public sealed record UntisClassAbsenceEntryDto(string StudentName, int? ExternKey, string ClassName, int Date,
+    int AbsentPeriods, int AbsentMinutes, string? TeacherUsernames, string? Subject, string? AbsenceReason,
+    string? Note, int? EntryId, string? HandledOn, bool Counts, string? ExcuseNote, int? PeriodNumber,
+    string? Status, bool CountsAsFullDay);
+
+/// <summary>Direkter WebUntis-Client des Desktops. Personenbezogene Antworten und der
+/// unverschlüsselte CSV-Report passieren zu keinem Zeitpunkt den LehrerApp-Server.</summary>
+public sealed class WebUntisIntegrationService(HttpClient http, WebUntisSettingsService settings) : IAsyncDisposable
+{
+    private readonly SemaphoreSlim _clientGate = new(1, 1);
+    private WebUntisClient? _client;
+
+    public bool IsAvailable => settings.ApiIsConfigured;
+
+    public async Task ConnectAsync(WebUntisCredentials credentials, CancellationToken token = default)
+    {
+        var candidate = CreateClient(credentials);
+        try
+        {
+            await candidate.GetSchoolYearsAsync(token);
+        }
+        catch (Exception exception) when (IsUntisError(exception))
+        {
+            await candidate.DisposeAsync();
+            throw Translate(exception);
+        }
+
+        WebUntisClient? previous;
+        await _clientGate.WaitAsync(token).ConfigureAwait(false);
+        try { previous = _client; _client = candidate; }
+        finally { _clientGate.Release(); }
+        if (previous is not null) await previous.DisposeAsync().ConfigureAwait(false);
+    }
+
+    public async Task DisconnectAsync(CancellationToken token = default)
+    {
+        WebUntisClient? previous;
+        await _clientGate.WaitAsync(token).ConfigureAwait(false);
+        try { previous = _client; _client = null; }
+        finally { _clientGate.Release(); }
+        if (previous is not null) await previous.DisposeAsync().ConfigureAwait(false);
+    }
+
+    public Task<IReadOnlyList<UntisSchoolYearDto>> GetSchoolYearsAsync(CancellationToken token = default) => ExecuteAsync(
+        async client => (IReadOnlyList<UntisSchoolYearDto>)(await client.GetSchoolYearsAsync(token))
+            .Select(x => new UntisSchoolYearDto(x.UntisId, x.Name, x.StartDate, x.EndDate)).ToList(), token);
+
+    public Task<IReadOnlyList<UntisClassDto>> GetClassesAsync(int schoolYearId, CancellationToken token = default) => ExecuteAsync(
+        async client => (IReadOnlyList<UntisClassDto>)(await client.GetClassesAsync(schoolYearId, token))
+            .Select(x => new UntisClassDto(x.UntisId, x.Name, x.LongName)).ToList(), token);
+
+    public Task<IReadOnlyList<UntisTeacherDto>> GetTeachersAsync(CancellationToken token = default) => ExecuteAsync(
+        async client => (IReadOnlyList<UntisTeacherDto>)(await client.GetTeachersAsync(token))
+            .Select(x => new UntisTeacherDto(x.UntisId, x.Name, x.ForeName, x.LongName, x.Title, x.Active,
+                x.DepartmentUntisIds)).ToList(), token);
+
+    public Task<IReadOnlyList<UntisTimeGridDayDto>> GetTimeGridAsync(CancellationToken token = default) => ExecuteAsync(
+        async client => (IReadOnlyList<UntisTimeGridDayDto>)(await client.GetTimeGridAsync(token))
+            .Select(x => new UntisTimeGridDayDto(x.Day,
+                x.TimeUnits.Select(t => new UntisTimeUnitDto(t.Name, t.StartTime, t.EndTime)).ToList())).ToList(), token);
+
+    public Task<IReadOnlyList<UntisTimetablePeriodDto>> GetTimetableAsync(int teacherId, DateOnly start,
+        DateOnly end, CancellationToken token = default) => ExecuteAsync(async client =>
+            (IReadOnlyList<UntisTimetablePeriodDto>)(await client.GetTimetableAsync(
+                UntisTimetableElementType.Teacher, teacherId, Date(start), Date(end), token))
+            .Select(x => new UntisTimetablePeriodDto(x.Id, x.Date, x.StartTime, x.EndTime, x.Code,
+                x.ActivityType, x.Info, x.LessonText, x.SubstitutionText, x.StudentGroup,
+                Entities(x.Classes), Entities(x.Teachers), Entities(x.Subjects), Entities(x.Rooms))).ToList(), token);
+
+    public Task<UntisStudentReportDto> GetStudentsAsync(string className, CancellationToken token = default) => ExecuteAsync(
+        async client =>
+        {
+            var report = await client.GetStudentReportAsync(className, token);
+            return new UntisStudentReportDto(report.Count, report.ClassNameFilter, report.Students.Select(x =>
+                new UntisStudentDto(x.UntisId, x.ExternKey, x.ClassName, x.Name, x.LongName, x.ForeName,
+                    x.DisplayName, x.Gender, x.BirthDate, x.BirthDateRaw, x.EntryDate, x.EntryDateRaw,
+                    x.ExitDate, x.ExitDateRaw, x.Text, x.MedicalReportDuty, x.Schulpflicht, x.Majority,
+                    new UntisStudentAddressDto(x.Address.Email, x.Address.Mobile, x.Address.Phone, x.Address.City,
+                        x.Address.PostCode, x.Address.Street), x.AttributeIL)).ToList());
+        }, token);
+
+    public Task<IReadOnlyList<UntisLessonAbsenceDto>> GetLessonAbsencesAsync(int lessonId,
+        DateOnly start, DateOnly end, CancellationToken token = default) => ExecuteAsync(async client =>
+    {
+        var absences = await client.GetLessonAbsencesAsync(lessonId, Date(start), Date(end), token);
+        return (IReadOnlyList<UntisLessonAbsenceDto>)absences.Select(x => new UntisLessonAbsenceDto(
+            x.StudentName, x.Date, x.AbsentPeriods, x.UnexcusedAbsentPeriods, x.AbsentMinutes,
+            x.UnexcusedAbsentMinutes, x.StartTime, x.EndTime, x.Reason, x.ExternKey, x.ExternKeyInParentheses,
+            x.HandledOn, x.Counts)).ToList();
+    }, token);
+
+    // "-alle-"-Bericht, hier auf eigene Einträge gefiltert (Benutzer == eigener WebUntis-Login) - Einträge
+    // anderer Lehrkräfte zu Schülern der eigenen Klasse gehören zu einem eigenständigen, noch nicht
+    // gebauten "Klassenlehrer"-Feature (siehe TODO.md), nicht zum reinen Dokumentations-Abgleich.
+    public Task<IReadOnlyList<UntisClassRegisterEventDto>> GetOwnClassRegisterEventsAsync(DateOnly start,
+        DateOnly end, CancellationToken token = default) => ExecuteAsync(async client =>
+    {
+        var ownUsername = settings.GetApiCredentials()?.Username;
+        var entries = await client.GetClassRegisterEventsReportAsync(Date(start), Date(end), token);
+        return (IReadOnlyList<UntisClassRegisterEventDto>)entries
+            .Where(x => ownUsername is not null
+                        && string.Equals(x.TeacherUsername, ownUsername, StringComparison.OrdinalIgnoreCase))
+            .Select(x => new UntisClassRegisterEventDto(x.ClassName, x.Date, x.Subject, x.StudentName,
+                x.CategoryName, x.CategoryGroup, x.Text))
+            .ToList();
+    }, token);
+
+    // Spiegelbild von GetOwnClassRegisterEventsAsync für das "Klassenlehrer"-Feature (siehe TODO.md):
+    // dieselben "-alle-"-Rohdaten, aber Einträge anderer Lehrkräfte statt der eigenen, zusätzlich auf
+    // die übergebene Klasse eingeschränkt (der "-alle-"-Bericht liefert sonst auch andere Klassen mit,
+    // sobald eine Lehrkraft mehrere Klassen unterrichtet).
+    public Task<IReadOnlyList<UntisForeignClassRegisterEventDto>> GetForeignClassRegisterEventsAsync(
+        string className, DateOnly start, DateOnly end, CancellationToken token = default) => ExecuteAsync(async client =>
+    {
+        var ownUsername = settings.GetApiCredentials()?.Username;
+        var entries = await client.GetClassRegisterEventsReportAsync(Date(start), Date(end), token);
+        return (IReadOnlyList<UntisForeignClassRegisterEventDto>)entries
+            .Where(x => string.Equals(x.ClassName, className, StringComparison.OrdinalIgnoreCase)
+                        // Nicht einfach "!=" gegen ownUsername: wäre ownUsername unbekannt (null), würde
+                        // ein ebenfalls fehlender TeacherUsername sonst fälschlich als "eigen" erkannt
+                        // (Equals(null,null)==true) und rausgefiltert statt als fremd angezeigt zu werden.
+                        && !(ownUsername is not null
+                             && string.Equals(x.TeacherUsername, ownUsername, StringComparison.OrdinalIgnoreCase)))
+            .Select(x => new UntisForeignClassRegisterEventDto(x.ClassName, x.Date, x.Subject, x.StudentName,
+                x.TeacherUsername, x.CategoryName, x.CategoryGroup, x.Text))
+            .ToList();
+    }, token);
+
+    // Fehlzeiten der ganzen Klasse über alle Fächer, Ergänzung zu GetForeignClassRegisterEventsAsync
+    // für das "Klassenlehrer"-Feature. Der Bericht adressiert die Klasse über "KL"+getKlassen-ID statt
+    // eines Namens, siehe ResolveClassIdAsync.
+    public Task<IReadOnlyList<UntisClassAbsenceEntryDto>> GetClassAbsencesAsync(string className,
+        DateOnly start, DateOnly end, CancellationToken token = default) => ExecuteAsync(async client =>
+    {
+        var classId = await ResolveClassIdAsync(client, className, token);
+        var entries = await client.GetClassAbsencesAsync(classId, Date(start), Date(end), token);
+        return (IReadOnlyList<UntisClassAbsenceEntryDto>)entries.Select(x => new UntisClassAbsenceEntryDto(
+            x.StudentName, x.ExternKey, x.ClassName, x.Date, x.AbsentPeriods, x.AbsentMinutes,
+            x.TeacherUsernames, x.Subject, x.AbsenceReason, x.Note, x.EntryId, x.HandledOn, x.Counts,
+            x.ExcuseNote, x.PeriodNumber, x.Status, x.CountsAsFullDay))
+            .ToList();
+    }, token);
+
+    // "KL" + getKlassen-ID, dasselbe Element-Kürzel-Schema wie kl/te/su/ro bei anderen Berichten
+    // (siehe Entities(...) unten). Unbestätigt (kein offizieller Report-Parameter dokumentiert), aber
+    // aus einem echten Browser-Request rückgeschlossen - schlägt die Zuordnung fehl, liefert der
+    // Bericht erkennbar leere/falsche Daten statt eines stillen Fehlers.
+    private static async Task<string> ResolveClassIdAsync(WebUntisClient client, string className,
+        CancellationToken token)
+    {
+        var years = await client.GetSchoolYearsAsync(token);
+        var today = Date(DateOnly.FromDateTime(DateTime.Today));
+        var year = years.FirstOrDefault(y => y.StartDate <= today && y.EndDate >= today)
+            ?? years.OrderByDescending(y => y.StartDate).FirstOrDefault()
+            ?? throw new WebUntisIntegrationException("WebUntis hat kein Schuljahr geliefert.");
+        var classes = await client.GetClassesAsync(year.UntisId, token);
+        var matches = classes.Where(c => string.Equals(c.Name, className, StringComparison.OrdinalIgnoreCase)).ToList();
+        return matches.Count switch
+        {
+            1 => $"KL{matches[0].UntisId}",
+            0 => throw new WebUntisIntegrationException($"WebUntis kennt keine Klasse namens \"{className}\"."),
+            _ => throw new WebUntisIntegrationException(
+                $"Mehrere WebUntis-Klassen heißen \"{className}\" - bitte manuell prüfen."),
+        };
+    }
+
+    private async Task<T> ExecuteAsync<T>(Func<WebUntisClient, Task<T>> operation, CancellationToken token)
+    {
+        try { return await operation(await GetClientAsync(token)); }
+        catch (Exception exception) when (IsUntisError(exception)) { throw Translate(exception); }
+    }
+
+    private async Task<WebUntisClient> GetClientAsync(CancellationToken token)
+    {
+        if (_client is not null) return _client;
+        await _clientGate.WaitAsync(token);
+        try
+        {
+            if (_client is not null) return _client;
+            var credentials = settings.GetApiCredentials()
+                ?? throw new WebUntisIntegrationException("Bitte zuerst die WebUntis-Anmeldedaten einrichten.");
+            return _client = CreateClient(credentials);
+        }
+        finally { _clientGate.Release(); }
+    }
+
+    private WebUntisClient CreateClient(WebUntisCredentials credentials) => new(http, new WebUntisOptions
+    {
+        School = credentials.School, Host = credentials.Host, Username = credentials.Username,
+        Password = credentials.Password, Client = "LehrerApp-Desktop", SessionIdleTimeoutMinutes = 10,
+    });
+
+    private static int Date(DateOnly date) => date.Year * 10000 + date.Month * 100 + date.Day;
+    private static IReadOnlyList<UntisEntityDto> Entities(IReadOnlyList<UntisEntity> values) => values
+        .Select(x => new UntisEntityDto(x.Id, x.Name, x.OriginalId, x.OriginalName, x.ExternalKey)).ToList();
+    private static bool IsUntisError(Exception exception) => exception is WebUntisException
+        or WebUntisConfigurationException or InvalidDataException;
+    private static WebUntisIntegrationException Translate(Exception exception) =>
+        new(exception.Message);
+
+    public async ValueTask DisposeAsync() => await DisconnectAsync().ConfigureAwait(false);
+}

LehrerApp.Desktop/Services/WebUntisSettingsService.cs

@@ -9,8 +9,14 @@ internal class WebUntisSettingsConfig
     public string? EncryptedIcalUrl { get; set; }
     public DateTime? LastSyncAt { get; set; }
     public string LastSyncStatus { get; set; } = "";
+    public string? EncryptedApiCredentials { get; set; }
+    public int? TeacherUntisId { get; set; }
+    public int? HomeroomClassUntisId { get; set; }
+    public string? HomeroomClassName { get; set; }
 }
 
+public sealed record WebUntisCredentials(string School, string Host, string Username, string Password);
+
 /// <summary>
 /// Einstellungen für den WebUntis-iCal-Abgleich (Nutzer-Feedback, siehe TODO.md). Liegt wie
 /// AiSettingsService/SyncSettingsService in LehrerApp.Desktop statt LehrerApp.Core, da die
@@ -30,6 +36,10 @@ public class WebUntisSettingsService
 
     public bool Enabled => _config.Enabled;
     public bool IsConfigured => _config.EncryptedIcalUrl is not null;
+    public bool ApiIsConfigured => _config.EncryptedApiCredentials is not null;
+    public int? TeacherUntisId => _config.TeacherUntisId;
+    public int? HomeroomClassUntisId => _config.HomeroomClassUntisId;
+    public string? HomeroomClassName => _config.HomeroomClassName;
     public DateTime? LastSyncAt => _config.LastSyncAt;
     public string LastSyncStatus => _config.LastSyncStatus;
 
@@ -63,6 +73,41 @@ public class WebUntisSettingsService
         Save();
     }
 
+    public void SetApiCredentials(WebUntisCredentials credentials)
+    {
+        _config.EncryptedApiCredentials = SyncCrypto.EncryptObject(credentials, _urlKey);
+        Save();
+    }
+
+    public WebUntisCredentials? GetApiCredentials() => _config.EncryptedApiCredentials is null
+        ? null
+        : SyncCrypto.DecryptObject<WebUntisCredentials>(_config.EncryptedApiCredentials, _urlKey);
+
+    public void ClearApiCredentials()
+    {
+        _config.EncryptedApiCredentials = null;
+        _config.TeacherUntisId = null;
+        _config.HomeroomClassUntisId = null;
+        _config.HomeroomClassName = null;
+        Save();
+    }
+
+    public void SetTeacherUntisId(int? teacherUntisId)
+    {
+        _config.TeacherUntisId = teacherUntisId;
+        Save();
+    }
+
+    // Die Klasse, deren Klassenlehrer/-in man ist - unabhängig von jeder LearningGroup (siehe
+    // TODO.md "Klassenlehrer"-Feature): man ist es für die ganze Klasse, nicht für einen einzelnen
+    // Unterricht/Kurs. HomeroomClassName ist wie TeacherUntisId unverschlüsselt, da kein Geheimnis.
+    public void SetHomeroomClass(int? untisId, string? name)
+    {
+        _config.HomeroomClassUntisId = untisId;
+        _config.HomeroomClassName = name;
+        Save();
+    }
+
     public void SetLastSync(DateTime at, string status)
     {
         _config.LastSyncAt = at;

LehrerApp.Desktop/Styles/SemanticBrushes.axaml

@@ -0,0 +1,74 @@
+<ResourceDictionary xmlns="https://github.com/avaloniaui"
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+  <!--
+    Semantische Pinsel für Flächen und Statusfarben (Klassenlehrer-Bereich, perspektivisch auch
+    die übrigen Ansichten). Hart codierte Hex-Werte in den Views waren auf das dunkle Theme
+    zugeschnitten und blieben beim Umschalten auf "Hell" stehen — dunkle Kartenflächen auf hellem
+    Fenstergrund, Statustexte ohne Kontrast. Über ThemeDictionaries tauscht Avalonia die Werte beim
+    Theme-Wechsel live aus, sofern die Views sie per DynamicResource (nicht StaticResource) holen.
+  -->
+  <ResourceDictionary.ThemeDictionaries>
+
+    <ResourceDictionary x:Key="Dark">
+      <!-- Flächen -->
+      <SolidColorBrush x:Key="AppCardBackgroundBrush" Color="#11151B"/>
+      <SolidColorBrush x:Key="AppCardBorderBrush" Color="#2A3038"/>
+      <SolidColorBrush x:Key="AppListRowBackgroundBrush" Color="#0E1217"/>
+      <SolidColorBrush x:Key="AppListRowHoverBrush" Color="#171D25"/>
+      <SolidColorBrush x:Key="AppListRowBorderBrush" Color="#262C34"/>
+      <SolidColorBrush x:Key="AppTrackBackgroundBrush" Color="#252B33"/>
+      <SolidColorBrush x:Key="AppChipBackgroundBrush" Color="#1C222A"/>
+      <SolidColorBrush x:Key="AppAvatarBorderBrush" Color="#4A515C"/>
+      <!-- Akzent -->
+      <SolidColorBrush x:Key="AppAccentTextBrush" Color="#5795F5"/>
+      <SolidColorBrush x:Key="AppAccentSoftBackgroundBrush" Color="#173765"/>
+      <SolidColorBrush x:Key="AppAccentOnSoftBrush" Color="#66A3FF"/>
+      <SolidColorBrush x:Key="AppFilterBorderBrush" Color="#343B45"/>
+      <SolidColorBrush x:Key="AppFilterActiveBackgroundBrush" Color="#173765"/>
+      <SolidColorBrush x:Key="AppFilterActiveBorderBrush" Color="#3C86F7"/>
+      <SolidColorBrush x:Key="AppFilterActiveForegroundBrush" Color="#FFFFFF"/>
+      <!-- Status: Nutzer-Feedback (August 2026) — Warnung (Amber) und Gefahr (Korallrot) waren
+           auf dem Bildschirm kaum auseinanderzuhalten. Per scripts/validate_palette.js der
+           dataviz-Skill gegen AppTrackBackgroundBrush/AppCardBackgroundBrush geprüft (adjacent
+           pairs, wie sie im gestapelten Balken tatsächlich aneinanderstoßen): die alte Kombi
+           lag bei ΔE nur 4.6–10.8 (protan/deutan), jetzt 10.2–24.4 — deutlich über der
+           Zielschwelle von 8. Ok/Warnung mussten zusätzlich im Tagesüberblick-Balken die
+           Reihenfolge tauschen (Info dazwischen), weil Grün und das validierte Dunkel-Gelb sonst
+           direkt aneinanderstießen (ΔE nur 3.0 unter Protanopie) — siehe
+           ClassTeacherOverviewView.axaml.
+           good=#008300, warning(dunkel)=#c98500, warning(hell)=#eda100, critical=#d03b3b
+           sind dieselben Stufen wie die validierte Kategorial-/Statuspalette der dataviz-Skill;
+           bewusst nicht wieder frei gewählt, um nicht erneut ins selbe Problem zu laufen. -->
+      <SolidColorBrush x:Key="AppStatusOkBrush" Color="#008300"/>
+      <SolidColorBrush x:Key="AppStatusInfoBrush" Color="#3987E5"/>
+      <SolidColorBrush x:Key="AppStatusWarningBrush" Color="#C98500"/>
+      <SolidColorBrush x:Key="AppStatusDangerBrush" Color="#D03B3B"/>
+    </ResourceDictionary>
+
+    <ResourceDictionary x:Key="Light">
+      <!-- Flächen: Karten heben sich hier heller vom grauen Fenstergrund ab, nicht dunkler. -->
+      <SolidColorBrush x:Key="AppCardBackgroundBrush" Color="#FFFFFF"/>
+      <SolidColorBrush x:Key="AppCardBorderBrush" Color="#DCE1E8"/>
+      <SolidColorBrush x:Key="AppListRowBackgroundBrush" Color="#FFFFFF"/>
+      <SolidColorBrush x:Key="AppListRowHoverBrush" Color="#EDF2F9"/>
+      <SolidColorBrush x:Key="AppListRowBorderBrush" Color="#E3E7ED"/>
+      <SolidColorBrush x:Key="AppTrackBackgroundBrush" Color="#E3E7ED"/>
+      <SolidColorBrush x:Key="AppChipBackgroundBrush" Color="#EDF0F5"/>
+      <SolidColorBrush x:Key="AppAvatarBorderBrush" Color="#B7BEC9"/>
+      <!-- Akzent: dunklere Töne, die Akzentfarben aus dem Dark-Theme wären auf Weiß zu blass. -->
+      <SolidColorBrush x:Key="AppAccentTextBrush" Color="#1B5FC7"/>
+      <SolidColorBrush x:Key="AppAccentSoftBackgroundBrush" Color="#DCE9FC"/>
+      <SolidColorBrush x:Key="AppAccentOnSoftBrush" Color="#14509F"/>
+      <SolidColorBrush x:Key="AppFilterBorderBrush" Color="#C7CDD6"/>
+      <SolidColorBrush x:Key="AppFilterActiveBackgroundBrush" Color="#D7E6FC"/>
+      <SolidColorBrush x:Key="AppFilterActiveBorderBrush" Color="#2C6FD8"/>
+      <SolidColorBrush x:Key="AppFilterActiveForegroundBrush" Color="#10243F"/>
+      <!-- Status: siehe Dark-Kommentar oben — dieselbe Validierung, helle Stufen. -->
+      <SolidColorBrush x:Key="AppStatusOkBrush" Color="#008300"/>
+      <SolidColorBrush x:Key="AppStatusInfoBrush" Color="#2A78D6"/>
+      <SolidColorBrush x:Key="AppStatusWarningBrush" Color="#EDA100"/>
+      <SolidColorBrush x:Key="AppStatusDangerBrush" Color="#D03B3B"/>
+    </ResourceDictionary>
+
+  </ResourceDictionary.ThemeDictionaries>
+</ResourceDictionary>

LehrerApp.Desktop/ViewModels/ClassTeacher/ClassTeacherDetailsViewModel.cs

@@ -0,0 +1,252 @@
+using System.Collections.ObjectModel;
+using CommunityToolkit.Mvvm.ComponentModel;
+using CommunityToolkit.Mvvm.Input;
+using LehrerApp.Desktop.Services;
+
+namespace LehrerApp.Desktop.ViewModels.ClassTeacher;
+
+/// <summary>Eine Zeile aus dem "-alle-"-Klassenbuchbericht, die eine andere Lehrkraft angelegt hat.
+/// Rein zur Ansicht - anders als beim Dokumentations-Abgleich (eigene Einträge) gibt es hier kein
+/// "Übernehmen", da es keine eigenen Einträge zum lokalen Synchronisieren sind.</summary>
+public sealed record ClassTeacherClassRegisterRow(DateOnly Date, string? Subject, string StudentName,
+    string? TeacherUsername, string? CategoryName, string? CategoryGroup, string? Text)
+{
+    public string DateLabel => Date.ToString("dd.MM.yyyy");
+    public string StudentDisplayName => DisplayName(StudentName);
+    public ClassTeacherStatusKind CategoryKind =>
+        CategoryGroup?.Contains("Negativ", StringComparison.OrdinalIgnoreCase) == true
+            ? ClassTeacherStatusKind.Danger : ClassTeacherStatusKind.Info;
+    public bool IsDangerStatus => CategoryKind == ClassTeacherStatusKind.Danger;
+    public bool IsInfoStatus => CategoryKind == ClassTeacherStatusKind.Info;
+
+    private static string DisplayName(string value)
+    {
+        var parts = value.Split(' ', StringSplitOptions.RemoveEmptyEntries);
+        return parts.Length < 2 ? value : string.Join(" ", parts.Skip(1).Append(parts[0]));
+    }
+}
+
+/// <summary>Zusammenfassung "wie oft welche Klassenbuch-Kategorie im Zeitraum, und bei wem am
+/// häufigsten" — Nutzer-Feedback: die reine Gesamtzahl ("12 Klassenbucheinträge") sagt wenig,
+/// eine Aufschlüsselung nach Kategorie ist die eigentlich interessante Information ("Hausaufgaben
+/// fehlen: 12×, davon 5× Ben"). Rein clientseitig aus den bereits geladenen <see cref="Entries"/>
+/// berechnet, kein zusätzlicher WebUntis-Abruf.</summary>
+public sealed record ClassTeacherCategoryAggregateRow(string CategoryName, int Count, string TopStudentsLabel)
+{
+    public string SummaryLabel => string.IsNullOrEmpty(TopStudentsLabel)
+        ? $"{Count}×" : $"{Count}× — {TopStudentsLabel}";
+
+    public static IReadOnlyList<ClassTeacherCategoryAggregateRow> Build(
+        IReadOnlyList<ClassTeacherClassRegisterRow> entries, int topStudentsPerCategory = 2) =>
+        entries.Where(e => !string.IsNullOrWhiteSpace(e.CategoryName))
+            .GroupBy(e => e.CategoryName!)
+            .Select(g =>
+            {
+                var topStudents = g.GroupBy(e => e.StudentDisplayName)
+                    .Select(sg => (Name: sg.Key, Count: sg.Count()))
+                    .OrderByDescending(sg => sg.Count).ThenBy(sg => sg.Name)
+                    .Take(topStudentsPerCategory)
+                    .Select(sg => $"{sg.Count}× {sg.Name}");
+                return new ClassTeacherCategoryAggregateRow(g.Key, g.Count(), string.Join(", ", topStudents));
+            })
+            .OrderByDescending(r => r.Count).ThenBy(r => r.CategoryName)
+            .ToList();
+}
+
+/// <summary>Fehlzeiten eines/einer Schüler*in an einem Tag, über alle Fächer zusammengefasst -
+/// der WebUntis-Bericht liefert eine Zeile pro Fehlstunde, was bei einer ganzen Klasse über mehrere
+/// Wochen zu unübersichtlich wäre (Nutzer-Feedback: kompakte "auf einen Blick"-Übersicht statt
+/// Rohdaten). Die Rohzeilen (<see cref="UntisClassAbsenceEntryDto"/>) bleiben trotzdem erreichbar,
+/// falls später ein Detail-Drill-down pro Schüler*in dazukommt (siehe TODO.md).</summary>
+public sealed record ClassAbsenceDaySummaryRow(DateOnly Date, string StudentName, int? ExternKey,
+    int TotalAbsentPeriods, int TotalAbsentMinutes, IReadOnlyList<string> Subjects,
+    IReadOnlyList<int> PeriodNumbers, IReadOnlyList<string> Statuses, IReadOnlyList<string> AbsenceReasons,
+    string? Note, string? ExcuseNote, bool CountsAsFullDay)
+{
+    public string DateLabel => Date.ToString("dd.MM.yyyy");
+    public string StudentDisplayName
+    {
+        get
+        {
+            var parts = StudentName.Split(' ', StringSplitOptions.RemoveEmptyEntries);
+            return parts.Length < 2 ? StudentName : string.Join(" ", parts.Skip(1).Append(parts[0]));
+        }
+    }
+    public string SubjectsLabel => string.Join(", ", Subjects);
+    public string PeriodsLabel => string.Join(", ", PeriodNumbers.Order());
+    public string StatusLabel => string.Join(", ", Statuses);
+    public string ReasonLabel => string.Join("; ", AbsenceReasons);
+    public bool IsLate => TotalAbsentPeriods == 0 || AbsenceReasons.Any(r =>
+        r.Contains("verspät", StringComparison.OrdinalIgnoreCase));
+    public bool IsUnexcused => Statuses.Any(s =>
+        s.Contains("nicht entsch", StringComparison.OrdinalIgnoreCase));
+    public string KindLabel => IsLate ? $"{TotalAbsentMinutes} Min. verspätet" :
+        CountsAsFullDay ? "Ganzer Fehltag" : $"{TotalAbsentPeriods} Fehlstunde{(TotalAbsentPeriods == 1 ? "" : "n")}";
+    public string FriendlyStatusLabel => IsUnexcused ? "Unentschuldigt" :
+        Statuses.Any(s => s.Contains("entsch", StringComparison.OrdinalIgnoreCase)) ? "Entschuldigt" : StatusLabel;
+    public ClassTeacherStatusKind StatusKind => IsUnexcused ? ClassTeacherStatusKind.Danger :
+        IsLate ? ClassTeacherStatusKind.Warning : ClassTeacherStatusKind.Ok;
+    public bool IsDangerStatus => StatusKind == ClassTeacherStatusKind.Danger;
+    public bool IsWarningStatus => StatusKind == ClassTeacherStatusKind.Warning;
+    public string DetailLabel => string.Join(" · ", new[] { ReasonLabel, Note, ExcuseNote }
+        .Where(value => !string.IsNullOrWhiteSpace(value)));
+
+    public static IReadOnlyList<ClassAbsenceDaySummaryRow> GroupByStudentAndDay(
+        IEnumerable<UntisClassAbsenceEntryDto> entries) => entries
+        .Select(e => (Entry: e, Date: TryDate(e.Date, out var d) ? d : (DateOnly?)null))
+        .Where(x => x.Date is not null)
+        .GroupBy(x => (Date: x.Date!.Value, x.Entry.StudentName, x.Entry.ExternKey))
+        .Select(g => new ClassAbsenceDaySummaryRow(
+            g.Key.Date, g.Key.StudentName, g.Key.ExternKey,
+            g.Sum(x => x.Entry.AbsentPeriods), g.Sum(x => x.Entry.AbsentMinutes),
+            Distinct(g.Select(x => x.Entry.Subject)),
+            g.Select(x => x.Entry.PeriodNumber).Where(p => p is not null).Select(p => p!.Value).Distinct().ToList(),
+            Distinct(g.Select(x => x.Entry.Status)),
+            Distinct(g.Select(x => x.Entry.AbsenceReason)),
+            g.Select(x => x.Entry.Note).FirstOrDefault(n => !string.IsNullOrWhiteSpace(n)),
+            g.Select(x => x.Entry.ExcuseNote).FirstOrDefault(n => !string.IsNullOrWhiteSpace(n)),
+            g.Any(x => x.Entry.CountsAsFullDay)))
+        .OrderByDescending(r => r.Date).ThenBy(r => r.StudentName)
+        .ToList();
+
+    private static List<string> Distinct(IEnumerable<string?> values) =>
+        values.Where(v => !string.IsNullOrWhiteSpace(v)).Select(v => v!).Distinct().ToList();
+
+    private static bool TryDate(int value, out DateOnly date) =>
+        DateOnly.TryParseExact(value.ToString(), "yyyyMMdd", out date);
+}
+
+/// <summary>
+/// Details-Ansicht des Klassenlehrer-Bereichs: Klassenbucheinträge, die andere Lehrkräfte zu
+/// Schülern der Klasse angelegt haben (WebUntis "-alle-"-Bericht, gefiltert auf fremde statt der
+/// eigenen Benutzerkennung wie beim bestehenden Dokumentations-Abgleich), sowie die Fehlzeiten der
+/// Klasse über alle Fächer — beide über <see cref="UntisReportCacheService"/> (lokal gecacht statt
+/// bei jedem Öffnen neu abgerufen, siehe TODO.md). Beides rein zur Ansicht, kein Übernehmen in
+/// lokale Daten. Bewusst unabhängig von jeder <see cref="Core.Models.LearningGroup"/> —
+/// Klassenlehrer ist man für die ganze Klasse, nicht für einen einzelnen Unterricht; die Klasse
+/// kommt aus <see cref="ClassTeacherOverviewViewModel"/> (letztlich aus den WebUntis-Einstellungen),
+/// nicht aus einer Gruppen-ID.
+/// </summary>
+public partial class ClassTeacherDetailsViewModel : ObservableObject
+{
+    private readonly UntisReportCacheService _cache;
+    private string _className = "";
+
+    public ObservableCollection<ClassTeacherClassRegisterRow> Entries { get; } = [];
+    public ObservableCollection<ClassAbsenceDaySummaryRow> AbsenceEntries { get; } = [];
+    public ObservableCollection<ClassTeacherCategoryAggregateRow> CategoryAggregates { get; } = [];
+
+    [ObservableProperty] private DateTimeOffset _startDate = DateTimeOffset.Now.AddDays(-6);
+    [ObservableProperty] private DateTimeOffset _endDate = DateTimeOffset.Now;
+    [ObservableProperty] private string _status = "Zeitraum wählen und laden.";
+    [ObservableProperty] private bool _busy;
+    /// Von der Übersicht gesetzt (Klick auf eine Roster-Zeile) - leer zeigt alle Schüler*innen.
+    [ObservableProperty] private string _studentFilter = "";
+    [ObservableProperty] private int _quickRangeIndex = 1;
+
+    public bool HasEntries => Entries.Count > 0;
+    public bool HasAbsenceEntries => AbsenceEntries.Count > 0;
+    public bool HasCategoryAggregates => CategoryAggregates.Count > 0;
+    public string ActiveFilterLabel => string.IsNullOrWhiteSpace(StudentFilter)
+        ? "Alle Schüler*innen" : StudentFilter;
+
+    public ClassTeacherDetailsViewModel(UntisReportCacheService cache)
+    {
+        _cache = cache;
+    }
+
+    public void Initialize(string className)
+    {
+        _className = className;
+        StudentFilter = "";
+        Entries.Clear();
+        AbsenceEntries.Clear();
+        CategoryAggregates.Clear();
+        Status = "Zeitraum wählen und laden.";
+        NotifyListState();
+    }
+
+    partial void OnStudentFilterChanged(string value) => OnPropertyChanged(nameof(ActiveFilterLabel));
+
+    partial void OnQuickRangeIndexChanged(int value)
+    {
+        var days = value switch { 0 => 0, 1 => 6, 2 => 29, _ => 6 };
+        EndDate = DateTimeOffset.Now;
+        StartDate = DateTimeOffset.Now.AddDays(-days);
+    }
+
+    [RelayCommand]
+    private Task Load() => LoadInternal(forceRefresh: false);
+
+    /// Umgeht bewusst die Stunden-Sperre von <see cref="UntisReportCacheService"/> — für den Fall,
+    /// dass man sicher weiß, dass sich seit dem letzten automatischen Abruf etwas geändert hat.
+    [RelayCommand]
+    private Task Refresh() => LoadInternal(forceRefresh: true);
+
+    [RelayCommand]
+    private Task ApplyFilter() => LoadInternal(forceRefresh: false);
+
+    [RelayCommand]
+    private async Task ClearStudentFilter()
+    {
+        StudentFilter = "";
+        await LoadInternal(forceRefresh: false);
+    }
+
+    private async Task LoadInternal(bool forceRefresh)
+    {
+        var start = DateOnly.FromDateTime(StartDate.LocalDateTime);
+        var end = DateOnly.FromDateTime(EndDate.LocalDateTime);
+        if (end < start) { Status = "Das Enddatum darf nicht vor dem Startdatum liegen."; return; }
+        if (string.IsNullOrWhiteSpace(_className)) { Status = "Keine Klasse ausgewählt."; return; }
+
+        Busy = true; Entries.Clear(); AbsenceEntries.Clear(); CategoryAggregates.Clear(); NotifyListState();
+        try
+        {
+            var classRegisterTask = _cache.GetClassRegisterEventsAsync(_className, start, end, forceRefresh);
+            var absencesTask = _cache.GetAbsencesAsync(_className, start, end, forceRefresh);
+            await Task.WhenAll(classRegisterTask, absencesTask);
+
+            var ordered = classRegisterTask.Result
+                .Where(MatchesStudentFilter)
+                .Select(e => (Entry: e, Date: TryDate(e.Date, out var d) ? d : (DateOnly?)null))
+                .Where(x => x.Date is not null)
+                .OrderByDescending(x => x.Date).ThenBy(x => x.Entry.StudentName);
+            foreach (var (entry, date) in ordered)
+            {
+                Entries.Add(new ClassTeacherClassRegisterRow(date!.Value, entry.Subject, entry.StudentName,
+                    entry.TeacherUsername, entry.CategoryName, entry.CategoryGroup, entry.Text));
+            }
+            foreach (var row in ClassTeacherCategoryAggregateRow.Build(Entries)) CategoryAggregates.Add(row);
+
+            var absences = absencesTask.Result.Where(MatchesStudentFilter);
+            foreach (var row in ClassAbsenceDaySummaryRow.GroupByStudentAndDay(absences))
+                AbsenceEntries.Add(row);
+
+            Status = $"{Entries.Count} Klassenbucheinträge anderer Lehrkräfte, " +
+                     $"{AbsenceEntries.Count} Fehlzeiten-Tage im Zeitraum.";
+            NotifyListState();
+        }
+        catch (WebUntisIntegrationException ex) { Status = ex.Message; }
+        finally { Busy = false; NotifyListState(); }
+    }
+
+    // WebUntis liefert Namen je nach Bericht in anderer Reihenfolge als der Schülerreport, aus dem
+    // StudentFilter beim Klick in der Übersicht gesetzt wird (siehe UntisNameMatching) - ein
+    // exakter String-Vergleich hier ließ die gefilterten Listen fälschlich leer erscheinen.
+    private bool MatchesStudentFilter(UntisForeignClassRegisterEventDto entry) =>
+        string.IsNullOrWhiteSpace(StudentFilter) || UntisNameMatching.NamesMatch(entry.StudentName, StudentFilter);
+
+    private bool MatchesStudentFilter(UntisClassAbsenceEntryDto entry) =>
+        string.IsNullOrWhiteSpace(StudentFilter) || UntisNameMatching.NamesMatch(entry.StudentName, StudentFilter);
+
+    private static bool TryDate(int value, out DateOnly date) =>
+        DateOnly.TryParseExact(value.ToString(), "yyyyMMdd", out date);
+
+    private void NotifyListState()
+    {
+        OnPropertyChanged(nameof(HasEntries));
+        OnPropertyChanged(nameof(HasAbsenceEntries));
+        OnPropertyChanged(nameof(HasCategoryAggregates));
+    }
+}

LehrerApp.Desktop/ViewModels/ClassTeacher/ClassTeacherOverviewViewModel.cs

@@ -0,0 +1,670 @@
+using System.Collections.ObjectModel;
+using CommunityToolkit.Mvvm.ComponentModel;
+using CommunityToolkit.Mvvm.Input;
+using LehrerApp.Core.Interfaces;
+using LehrerApp.Core.Models;
+using LehrerApp.Core.Services;
+using LehrerApp.Desktop.Services;
+
+namespace LehrerApp.Desktop.ViewModels.ClassTeacher;
+
+/// <summary>Semantische Statusstufe einer Zeile bzw. eines Hinweises. Bewusst ohne Farbwert im
+/// ViewModel: Die Zuordnung zu einem Pinsel passiert über Style-Klassen in XAML
+/// (<c>Styles/SemanticBrushes.axaml</c>), damit ein Theme-Wechsel hell/dunkel sie live mitnimmt —
+/// ein hart codierter Hex-String aus dem ViewModel bliebe beim Wechsel unverändert stehen.</summary>
+public enum ClassTeacherStatusKind { Ok, Info, Warning, Danger }
+
+public sealed record ClassTeacherRosterRow(string StudentName, int? ExternKey, bool HasAbsenceToday,
+    string? AbsenceTooltip, bool HasRecentClassRegisterEntry)
+{
+    public ClassAbsenceDaySummaryRow? TodayAbsence { get; init; }
+    public bool HasClassRegisterToday { get; init; }
+    public bool IsLate => TodayAbsence is { } a &&
+        (a.TotalAbsentPeriods == 0 || a.AbsenceReasons.Any(IsLateReason));
+    public bool IsUnexcused => TodayAbsence?.Statuses.Any(s =>
+        s.Contains("nicht entsch", StringComparison.OrdinalIgnoreCase)) == true;
+    public bool NeedsAttention => HasAbsenceToday || HasRecentClassRegisterEntry;
+    public int AttentionRank => IsUnexcused ? 0 : IsLate ? 1 : HasAbsenceToday ? 2 :
+        HasRecentClassRegisterEntry ? 3 : 4;
+
+    public string Initials
+    {
+        get
+        {
+            var parts = StudentName.Split(' ', StringSplitOptions.RemoveEmptyEntries);
+            return string.Concat(parts.Take(2).Select(p => char.ToUpperInvariant(p[0])));
+        }
+    }
+
+    public string StatusText
+    {
+        get
+        {
+            if (TodayAbsence is null)
+                return HasRecentClassRegisterEntry ? "Neuer Klassenbucheintrag" : "Keine gemeldete Fehlzeit";
+            var core = IsLate
+                ? $"{TodayAbsence.TotalAbsentMinutes} Min. verspätet"
+                : TodayAbsence.CountsAsFullDay
+                    ? "Ganzer Fehltag"
+                    : $"{TodayAbsence.TotalAbsentPeriods} Fehlstunde{(TodayAbsence.TotalAbsentPeriods == 1 ? "" : "n")}";
+            return IsUnexcused ? $"{core} · Unentschuldigt" : core;
+        }
+    }
+
+    public ClassTeacherStatusKind StatusKind => IsUnexcused ? ClassTeacherStatusKind.Danger :
+        HasAbsenceToday ? ClassTeacherStatusKind.Warning :
+        HasRecentClassRegisterEntry ? ClassTeacherStatusKind.Info : ClassTeacherStatusKind.Ok;
+    public bool IsDangerStatus => StatusKind == ClassTeacherStatusKind.Danger;
+    public bool IsWarningStatus => StatusKind == ClassTeacherStatusKind.Warning;
+    public bool IsInfoStatus => StatusKind == ClassTeacherStatusKind.Info;
+    public string ClassRegisterLabel => HasClassRegisterToday ? "Eintrag heute" :
+        HasRecentClassRegisterEntry ? "Eintrag diese Woche" : "";
+
+    /// Quick-Win Barrierefreiheit: der Status wurde bislang ausschließlich über die Farbe des
+    /// linken Balkens/Texts transportiert. Ein kleines vorangestelltes Symbol macht Warnung/Gefahr
+    /// auch ohne verlässliche Farbunterscheidung erkennbar (und beim schnellen Scannen der Liste).
+    public string StatusTextWithGlyph => StatusKind switch
+    {
+        ClassTeacherStatusKind.Danger => $"✕ {StatusText}",
+        ClassTeacherStatusKind.Warning => $"△ {StatusText}",
+        _ => StatusText,
+    };
+
+    /// Kumulierte Fehlzeiten seit Schuljahresbeginn (Nutzer-Feedback: der Heute-Snapshot allein
+    /// sagt für Zeugnis/Attestpflicht wenig aus). <see cref="SchoolDaysElapsed"/> zählt nur
+    /// Werktage, ohne Ferienkalender — eine bewusste Vereinfachung, siehe TODO.md 12.4-Nachtrag.
+    public int YearAbsenceDayCount { get; init; }
+    public int YearUnexcusedDayCount { get; init; }
+    public int SchoolDaysElapsed { get; init; }
+    public bool HasYearSummary => SchoolDaysElapsed > 0 && YearAbsenceDayCount > 0;
+    public int YearAbsenceRatePercent =>
+        SchoolDaysElapsed <= 0 ? 0 : (int)Math.Round(100d * YearAbsenceDayCount / SchoolDaysElapsed);
+    public string YearSummaryLabel => HasYearSummary
+        ? $"{YearAbsenceRatePercent} % Fehlzeit seit Schuljahresbeginn" : "";
+    public string? YearSummaryTooltip => !HasYearSummary ? null :
+        $"{YearAbsenceDayCount} von {SchoolDaysElapsed} Schultagen mit Fehlzeit" +
+        (YearUnexcusedDayCount > 0 ? $" · {YearUnexcusedDayCount} unentschuldigt" : "");
+
+    private static bool IsLateReason(string reason) =>
+        reason.Contains("verspät", StringComparison.OrdinalIgnoreCase);
+
+    public static IReadOnlyList<ClassTeacherRosterRow> Build(
+        IReadOnlyList<UntisStudentRosterCacheEntry> students,
+        IReadOnlyList<ClassAbsenceDaySummaryRow> todayAbsences,
+        IReadOnlyList<UntisForeignClassRegisterEventDto> recentClassRegisterEntries,
+        DateOnly? today = null,
+        IReadOnlyList<ClassAbsenceDaySummaryRow>? yearAbsences = null,
+        int schoolDaysElapsed = 0)
+    {
+        var referenceDate = today ?? todayAbsences.FirstOrDefault()?.Date ?? DateOnly.FromDateTime(DateTime.Today);
+        var absenceByKey = todayAbsences.Where(a => a.ExternKey is not null)
+            .GroupBy(a => a.ExternKey!.Value).ToDictionary(g => g.Key, g => g.First());
+        var absenceByName = todayAbsences.GroupBy(a => UntisNameMatching.NameKey(a.StudentName))
+            .ToDictionary(g => g.Key, g => g.First());
+        var recentByName = recentClassRegisterEntries.GroupBy(e => UntisNameMatching.NameKey(e.StudentName))
+            .ToDictionary(g => g.Key, g => g.ToList());
+        var yearRows = yearAbsences ?? [];
+        var yearByKey = yearRows.Where(a => a.ExternKey is not null)
+            .GroupBy(a => a.ExternKey!.Value).ToDictionary(g => g.Key, g => g.ToList());
+        var yearByName = yearRows.GroupBy(a => UntisNameMatching.NameKey(a.StudentName))
+            .ToDictionary(g => g.Key, g => g.ToList());
+
+        return students.Select(student =>
+            {
+                var nameKey = UntisNameMatching.NameKey(student.DisplayName);
+                var absence = (student.ExternKey is { } key ? absenceByKey.GetValueOrDefault(key) : null)
+                    ?? absenceByName.GetValueOrDefault(nameKey);
+                var registerEntries = recentByName.GetValueOrDefault(nameKey) ?? [];
+                var yearEntries = (student.ExternKey is { } yearKey ? yearByKey.GetValueOrDefault(yearKey) : null)
+                    ?? yearByName.GetValueOrDefault(nameKey) ?? [];
+                return new ClassTeacherRosterRow(student.DisplayName, student.ExternKey, absence is not null,
+                    absence is null ? null : $"{absence.TotalAbsentPeriods} Stunde(n) — {absence.StatusLabel}",
+                    registerEntries.Count > 0)
+                {
+                    TodayAbsence = absence,
+                    HasClassRegisterToday = registerEntries.Any(e => TryDate(e.Date, out var date) && date == referenceDate),
+                    YearAbsenceDayCount = yearEntries.Count,
+                    YearUnexcusedDayCount = yearEntries.Count(r => r.IsUnexcused),
+                    SchoolDaysElapsed = schoolDaysElapsed,
+                };
+            })
+            .OrderBy(r => r.AttentionRank).ThenBy(r => r.StudentName).ToList();
+    }
+
+    private static bool TryDate(int value, out DateOnly date) =>
+        DateOnly.TryParseExact(value.ToString(), "yyyyMMdd", out date);
+}
+
+/// Ein gestapelter Tages-Balken statt drei unabhängig skalierter (Nutzer-Feedback: die vorherige
+/// Version zeigte Alerts/Unentschuldigt/Verspätet als drei separate, gleich hohe Balken, obwohl
+/// Unentschuldigt und Verspätet Teilmengen von Alerts sind — das suggerierte fälschlich drei
+/// unabhängige Größen). Die drei Segmente sind überschneidungsfrei (Unentschuldigt hat Vorrang
+/// vor Verspätet, wie bei <see cref="ClassTeacherRosterRow.AttentionRank"/>).
+public sealed record ClassTeacherTrendDay(string DayLabel, int AlertCount, int UnexcusedCount,
+    int LateExcusedCount, int ExcusedCount, double UnexcusedFraction, double LateExcusedFraction,
+    double ExcusedFraction)
+{
+    /// Anteile 0…1 des höchsten Tages der letzten 7 Schultage statt fester Pixelbreiten
+    /// (Quick-Win, Nutzer-Feedback: die Balkenbreite hing bisher an einer im ViewModel hart
+    /// codierten Pixelkonstante, die mit der tatsächlichen Breite der Seitenspalte in XAML
+    /// synchron gehalten werden musste). Die View multipliziert diese Anteile per MultiBinding
+    /// (<see cref="LehrerApp.Desktop.Converters.FractionWidthConverter"/>) mit der tatsächlich gerenderten Breite
+    /// der Track-Leiste — bleibt damit auch dann korrekt, wenn die Seitenspalte mal eine andere
+    /// Breite bekommt. <c>Grid.ColumnDefinitions</c> ließ sich dafür nicht binden (kein Setter bei
+    /// kompilierten Bindings, AVLN3000), deshalb Pixelbreite statt Grid-Sternspalten.
+    public double TotalFraction => UnexcusedFraction + LateExcusedFraction + ExcusedFraction;
+    public string DetailTooltip =>
+        $"{UnexcusedCount} unentschuldigt · {LateExcusedCount} verspätet · {ExcusedCount} entschuldigt";
+}
+public sealed record ClassTeacherPatternNotice(string StudentName, string Message,
+    ClassTeacherStatusKind Kind)
+{
+    public bool IsDangerStatus => Kind == ClassTeacherStatusKind.Danger;
+    public bool IsWarningStatus => Kind == ClassTeacherStatusKind.Warning;
+    public bool IsInfoStatus => Kind == ClassTeacherStatusKind.Info;
+}
+
+/// <summary>Ein Fehltag, der aktuell (Stand letztem Abruf) als unentschuldigt geführt wird —
+/// Nutzer-Feedback: die Übersicht zeigte bislang nur den Heute-Snapshot und einen 7-Tage-Trend,
+/// aber keine Liste konkreter offener Fälle, die man abarbeiten könnte. Läuft über die ohnehin
+/// für die Jahresfehlquote geladenen Daten (<see cref="ClassTeacherOverviewViewModel.Load"/>),
+/// kein zusätzlicher Abruf.</summary>
+public sealed record ClassTeacherOpenExcuseRow(string StudentName, DateOnly Date, int DaysOpen)
+{
+    /// Verbreitete Regelung in vielen Bundesländern: Entschuldigung "innerhalb von drei Tagen"
+    /// nach der Fehlzeit (z.B. § 43 Abs. 2 SchulG NRW). Nur ein Richtwert für die optische
+    /// Hervorhebung hier — WebUntis liefert keine schulspezifische Frist, und die tatsächliche
+    /// Regelung kann je nach Bundesland/Schulordnung abweichen.
+    public const int DeadlineDays = 3;
+    public string DateLabel => Date.ToString("dd.MM.");
+    public bool IsOverdue => DaysOpen > DeadlineDays;
+    public string DaysOpenLabel => $"seit {DaysOpen} Tag{(DaysOpen == 1 ? "" : "en")} unentschuldigt";
+
+    public static IReadOnlyList<ClassTeacherOpenExcuseRow> Build(
+        IReadOnlyList<ClassAbsenceDaySummaryRow> absenceDays, DateOnly today) =>
+        absenceDays.Where(a => a.IsUnexcused)
+            .Select(a => new ClassTeacherOpenExcuseRow(a.StudentDisplayName, a.Date,
+                today.DayNumber - a.Date.DayNumber))
+            .OrderByDescending(r => r.DaysOpen).ThenBy(r => r.StudentName)
+            .ToList();
+}
+
+public partial class ClassTeacherOverviewViewModel : ObservableObject
+{
+    private readonly WebUntisSettingsService _settings;
+    private readonly UntisReportCacheService _cache;
+    private readonly SchoolYearService _schoolYear;
+    private readonly IWorkTaskRepository _workTasks;
+    private readonly IStudentRepository _students;
+    private readonly IParticipationRepository _participation;
+    private readonly IParticipationSessionRepository _participationSessions;
+
+    public ClassTeacherDetailsViewModel DetailsTab { get; }
+    public ObservableCollection<ClassTeacherRosterRow> Roster { get; } = [];
+    public ObservableCollection<ClassTeacherRosterRow> PrimaryRoster { get; } = [];
+    public ObservableCollection<ClassTeacherRosterRow> SecondaryRoster { get; } = [];
+    public ObservableCollection<ClassTeacherTrendDay> TrendDays { get; } = [];
+    public ObservableCollection<ClassTeacherPatternNotice> PatternNotices { get; } = [];
+    public ObservableCollection<ClassTeacherOpenExcuseRow> OpenExcuses { get; } = [];
+
+    [ObservableProperty] private string? _homeroomClassName;
+    [ObservableProperty] private int _activeTabIndex;
+    [ObservableProperty] private string _status = "";
+    [ObservableProperty] private bool _busy;
+    [ObservableProperty] private string _searchText = "";
+    [ObservableProperty] private int _selectedRosterFilter;
+    [ObservableProperty] private string _primarySectionTitle = "Heute auffällig";
+    [ObservableProperty] private string _secondarySectionTitle = "Weitere Schüler*innen";
+    [ObservableProperty] private int _studentCount;
+    [ObservableProperty] private int _todayAlertCount;
+    [ObservableProperty] private int _todayUnexcusedCount;
+    [ObservableProperty] private int _recentClassRegisterCount;
+    [ObservableProperty] private int _presentCount;
+    [ObservableProperty] private int _lateCount;
+    [ObservableProperty] private int _excusedAbsenceCount;
+    [ObservableProperty] private int _unexcusedAbsenceCount;
+    [ObservableProperty] private string _lastUpdatedLabel = "Noch nicht aktualisiert";
+    [ObservableProperty] private int _openExcuseOverflowCount;
+
+    public bool HomeroomClassConfigured => !string.IsNullOrWhiteSpace(HomeroomClassName);
+    public bool HasPrimaryRoster => PrimaryRoster.Count > 0;
+    public bool HasSecondaryRoster => SecondaryRoster.Count > 0;
+    public bool HasNoFilterResults => !Busy && PrimaryRoster.Count == 0 && SecondaryRoster.Count == 0;
+    public bool HasPatternNotices => PatternNotices.Count > 0;
+    public bool HasOpenExcuses => OpenExcuses.Count > 0;
+    public bool HasOpenExcuseOverflow => OpenExcuseOverflowCount > 0;
+    public bool AlertsFilterSelected => SelectedRosterFilter == 0;
+    public bool ClassRegisterFilterSelected => SelectedRosterFilter == 1;
+    public bool AllFilterSelected => SelectedRosterFilter == 2;
+    public int TodayUnexcusedPercent => Percent(TodayUnexcusedCount);
+    public int LatePercent => Percent(LateCount);
+    public int PresentPercent => Percent(PresentCount);
+    public int ExcusedAbsencePercent => Percent(ExcusedAbsenceCount);
+    public int UnexcusedAbsencePercent => Percent(UnexcusedAbsenceCount);
+
+    /// Quick-Win: <see cref="TodayUnexcusedPercent"/> wurde berechnet, aber nirgends gebunden —
+    /// jetzt als zweite Zeile in der "unentschuldigt"-Kennzahlkarte sichtbar.
+    public string TodayUnexcusedSummaryLabel => $"unentschuldigt · {TodayUnexcusedPercent} %";
+
+    /// Beschriftungen für den kompakten Tagesüberblick (Quick-Win: ein gestapelter 100-%-Balken
+    /// statt vier Einzelzeilen mit separater Prozentspalte — Zahl und Anteil jetzt in einer
+    /// Zeile). Die vier Kategorien sind exklusiv und summieren sich exakt zu StudentCount, siehe
+    /// die Herleitung von Present-/Late-/Excused-/UnexcusedAbsenceCount in <see cref="Load"/>.
+    public string PresentSummaryLabel => $"{PresentCount} Anwesend · {PresentPercent} %";
+    public string LateSummaryLabel => $"{LateCount} Verspätet · {LatePercent} %";
+    public string ExcusedAbsenceSummaryLabel => $"{ExcusedAbsenceCount} Entschuldigt · {ExcusedAbsencePercent} %";
+    public string UnexcusedAbsenceSummaryLabel => $"{UnexcusedAbsenceCount} Unentschuldigt · {UnexcusedAbsencePercent} %";
+    /// Anteile 0…1 für den gestapelten Tagesüberblick-Balken (View multipliziert per MultiBinding
+    /// mit der gerenderten Track-Breite, siehe <see cref="ClassTeacherTrendDay.TotalFraction"/>
+    /// für dasselbe Muster beim Trend-Chart). Die vier Kategorien sind exklusiv und summieren sich
+    /// zu 1, da StudentCount == Present + Late + ExcusedAbsence + UnexcusedAbsence.
+    public double PresentFraction => StudentCount == 0 ? 0 : (double)PresentCount / StudentCount;
+    public double LateFraction => StudentCount == 0 ? 0 : (double)LateCount / StudentCount;
+    public double ExcusedAbsenceFraction => StudentCount == 0 ? 0 : (double)ExcusedAbsenceCount / StudentCount;
+    public double UnexcusedAbsenceFraction => StudentCount == 0 ? 0 : (double)UnexcusedAbsenceCount / StudentCount;
+    public string DayOverviewTooltip => $"{PresentCount} anwesend · {LateCount} verspätet · " +
+        $"{ExcusedAbsenceCount} entschuldigt · {UnexcusedAbsenceCount} unentschuldigt";
+
+    public Func<Task>? OnNavigateToSettings { get; set; }
+    public Func<Task>? OnNavigateToWorkload { get; set; }
+
+    public ClassTeacherOverviewViewModel(WebUntisSettingsService settings,
+        UntisReportCacheService cache, SchoolYearService schoolYear, IWorkTaskRepository workTasks,
+        IStudentRepository students, IParticipationRepository participation,
+        IParticipationSessionRepository participationSessions, ClassTeacherDetailsViewModel detailsTab)
+    {
+        _settings = settings;
+        _cache = cache;
+        _schoolYear = schoolYear;
+        _workTasks = workTasks;
+        _students = students;
+        _participation = participation;
+        _participationSessions = participationSessions;
+        DetailsTab = detailsTab;
+    }
+
+    partial void OnHomeroomClassNameChanged(string? value) => OnPropertyChanged(nameof(HomeroomClassConfigured));
+    partial void OnOpenExcuseOverflowCountChanged(int value) => OnPropertyChanged(nameof(HasOpenExcuseOverflow));
+    partial void OnSearchTextChanged(string value) => ApplyRosterFilter();
+    partial void OnSelectedRosterFilterChanged(int value)
+    {
+        OnPropertyChanged(nameof(AlertsFilterSelected));
+        OnPropertyChanged(nameof(ClassRegisterFilterSelected));
+        OnPropertyChanged(nameof(AllFilterSelected));
+        ApplyRosterFilter();
+    }
+
+    [RelayCommand]
+    private async Task Load()
+    {
+        HomeroomClassName = _settings.HomeroomClassName;
+        ActiveTabIndex = 0;
+        Roster.Clear(); PrimaryRoster.Clear(); SecondaryRoster.Clear(); TrendDays.Clear(); PatternNotices.Clear();
+        OpenExcuses.Clear(); OpenExcuseOverflowCount = 0;
+        if (!HomeroomClassConfigured)
+        {
+            Status = "Noch keine Klasse ausgewählt.";
+            NotifyRosterState();
+            return;
+        }
+
+        var className = HomeroomClassName!;
+        DetailsTab.Initialize(className);
+        Busy = true;
+        NotifyRosterState();
+        try
+        {
+            var today = DateOnly.FromDateTime(DateTime.Today);
+            var sevenDayStart = today.AddDays(-6);
+            var trendDays = LastSchoolDays(today, 7);
+            // Fehlzeiten seit Schuljahresbeginn statt nur der letzten 7 Tage: liefert die
+            // Kennzahl unten (YearSummaryLabel) und den Nenner für die Fehlquote in einem Abruf.
+            // UntisReportCacheService cached diesen "kalten" Bereich dauerhaft (siehe dort) —
+            // teuer ist nur der erste Abruf pro Schuljahr, nicht jedes Öffnen der Ansicht.
+            var yearStart = _schoolYear.SchoolYearStart(_schoolYear.CurrentSchoolYear(today));
+            var studentsTask = _cache.GetStudentRosterAsync(className);
+            var absencesTask = _cache.GetAbsencesAsync(className, yearStart, today);
+            var classRegisterTask = _cache.GetClassRegisterEventsAsync(className, sevenDayStart, today);
+            await Task.WhenAll(studentsTask, absencesTask, classRegisterTask);
+
+            var absenceDaysYear = ClassAbsenceDaySummaryRow.GroupByStudentAndDay(absencesTask.Result);
+            var todayAbsences = absenceDaysYear.Where(a => a.Date == today).ToList();
+            var weekAbsenceDays = absenceDaysYear.Where(a => a.Date >= sevenDayStart).ToList();
+            var schoolDaysElapsed = CountWeekdays(yearStart, today);
+            foreach (var row in ClassTeacherRosterRow.Build(studentsTask.Result, todayAbsences,
+                         classRegisterTask.Result, today, absenceDaysYear, schoolDaysElapsed)) Roster.Add(row);
+
+            StudentCount = Roster.Count;
+            TodayAlertCount = Roster.Count(r => r.HasAbsenceToday);
+            TodayUnexcusedCount = Roster.Count(r => r.IsUnexcused);
+            LateCount = Roster.Count(r => r.IsLate);
+            PresentCount = Roster.Count(r => !r.HasAbsenceToday);
+            ExcusedAbsenceCount = Roster.Count(r => r.HasAbsenceToday && !r.IsLate && !r.IsUnexcused);
+            UnexcusedAbsenceCount = Roster.Count(r => r.HasAbsenceToday && !r.IsLate && r.IsUnexcused);
+            RecentClassRegisterCount = classRegisterTask.Result.Count;
+            BuildTrend(absenceDaysYear, trendDays);
+            BuildPatternNotices(weekAbsenceDays);
+            BuildWeekdayPatternNotices(absenceDaysYear);
+            BuildAttendanceParticipationNotices();
+            BuildOpenExcuses(absenceDaysYear, today);
+            LastUpdatedLabel = $"Zuletzt aktualisiert: Heute, {DateTime.Now:HH:mm}";
+            Status = $"{StudentCount} Schüler*innen · {TodayAlertCount} heute auffällig";
+            ApplyRosterFilter();
+            NotifySummary();
+        }
+        catch (WebUntisIntegrationException ex) { Status = ex.Message; NotifyRosterState(); }
+        finally { Busy = false; NotifyRosterState(); }
+    }
+
+    [RelayCommand] private void ShowAlerts() => SelectedRosterFilter = 0;
+    [RelayCommand] private void ShowClassRegister() => SelectedRosterFilter = 1;
+    [RelayCommand] private void ShowAll() => SelectedRosterFilter = 2;
+
+    [RelayCommand]
+    private void OpenClassRegister()
+    {
+        DetailsTab.StudentFilter = "";
+        ActiveTabIndex = 1;
+        DetailsTab.LoadCommand.Execute(null);
+    }
+
+    [RelayCommand]
+    private void OpenAbsences()
+    {
+        DetailsTab.StudentFilter = "";
+        ActiveTabIndex = 2;
+        DetailsTab.LoadCommand.Execute(null);
+    }
+
+    [RelayCommand]
+    private void ShowDetailsForStudent(ClassTeacherRosterRow? row)
+    {
+        if (row is null) return;
+        DetailsTab.StudentFilter = row.StudentName;
+        ActiveTabIndex = row.HasAbsenceToday ? 2 : 1;
+        DetailsTab.LoadCommand.Execute(null);
+    }
+
+    [RelayCommand] private async Task GoToSettings()
+    { if (OnNavigateToSettings is not null) await OnNavigateToSettings(); }
+
+    [RelayCommand] private async Task GoToWorkload()
+    { if (OnNavigateToWorkload is not null) await OnNavigateToWorkload(); }
+
+    private void ApplyRosterFilter()
+    {
+        PrimaryRoster.Clear(); SecondaryRoster.Clear();
+        var query = Roster.Where(r => string.IsNullOrWhiteSpace(SearchText) ||
+            r.StudentName.Contains(SearchText.Trim(), StringComparison.CurrentCultureIgnoreCase));
+        if (SelectedRosterFilter == 0)
+        {
+            PrimarySectionTitle = "Heute auffällig";
+            foreach (var row in query.Where(r => r.HasAbsenceToday)) PrimaryRoster.Add(row);
+        }
+        else if (SelectedRosterFilter == 1)
+        {
+            PrimarySectionTitle = "Klassenbucheinträge der letzten 7 Tage";
+            foreach (var row in query.Where(r => r.HasRecentClassRegisterEntry)) PrimaryRoster.Add(row);
+        }
+        else
+        {
+            PrimarySectionTitle = "Heute auffällig";
+            SecondarySectionTitle = "Weitere Schüler*innen";
+            foreach (var row in query.Where(r => r.NeedsAttention)) PrimaryRoster.Add(row);
+            foreach (var row in query.Where(r => !r.NeedsAttention)) SecondaryRoster.Add(row);
+        }
+        NotifyRosterState();
+    }
+
+    /// Letzte <paramref name="days"/> statt letzte 7 Kalendertage (Nutzer-Feedback: an zwei von
+    /// sieben Tagen war der Trend bislang systematisch leer, weil Wochenenden mitzählten). Ohne
+    /// Ferienkalender — siehe <see cref="LastSchoolDays"/>.
+    private void BuildTrend(IReadOnlyList<ClassAbsenceDaySummaryRow> absenceDays, IReadOnlyList<DateOnly> days)
+    {
+        var today = days[^1];
+        var counts = days.Select(date =>
+        {
+            var rows = absenceDays.Where(r => r.Date == date).ToList();
+            var unexcused = rows.Count(r => r.IsUnexcused);
+            var lateExcused = rows.Count(r => !r.IsUnexcused && r.IsLate);
+            var excused = rows.Count(r => !r.IsUnexcused && !r.IsLate);
+            return (Date: date, Unexcused: unexcused, LateExcused: lateExcused, Excused: excused,
+                Total: unexcused + lateExcused + excused);
+        }).ToList();
+        var max = Math.Max(1, counts.Max(c => c.Total));
+        foreach (var day in counts)
+            TrendDays.Add(new ClassTeacherTrendDay(day.Date == today ? "Heute" : day.Date.ToString("ddd"),
+                day.Total, day.Unexcused, day.LateExcused, day.Excused,
+                (double)day.Unexcused / max, (double)day.LateExcused / max, (double)day.Excused / max));
+    }
+
+    /// Letzte <paramref name="count"/> Werktage bis einschließlich <paramref name="end"/>, ohne
+    /// Ferienkalender (bewusste Vereinfachung, siehe TODO.md 12.4-Nachtrag) — die App kennt keine
+    /// Schulferien, nur Wochenenden.
+    private static IReadOnlyList<DateOnly> LastSchoolDays(DateOnly end, int count)
+    {
+        var days = new List<DateOnly>();
+        for (var cursor = end; days.Count < count; cursor = cursor.AddDays(-1))
+            if (cursor.DayOfWeek is not (DayOfWeek.Saturday or DayOfWeek.Sunday))
+                days.Add(cursor);
+        days.Reverse();
+        return days;
+    }
+
+    /// Nenner für <see cref="ClassTeacherRosterRow.YearAbsenceRatePercent"/> — Werktage zwischen
+    /// Schuljahresbeginn und heute, ebenfalls ohne Ferienkalender.
+    private static int CountWeekdays(DateOnly start, DateOnly end)
+    {
+        if (end < start) return 0;
+        var count = 0;
+        for (var d = start; d <= end; d = d.AddDays(1))
+            if (d.DayOfWeek is not (DayOfWeek.Saturday or DayOfWeek.Sunday)) count++;
+        return count;
+    }
+
+    private void BuildPatternNotices(IReadOnlyList<ClassAbsenceDaySummaryRow> absenceDays)
+    {
+        foreach (var group in absenceDays.GroupBy(row => UntisNameMatching.NameKey(row.StudentName)))
+        {
+            var rows = group.ToList();
+            var displayName = Roster.FirstOrDefault(row =>
+                UntisNameMatching.NameKey(row.StudentName) == group.Key)?.StudentName ?? rows[0].StudentDisplayName;
+            var lateDays = rows.Count(row => row.IsLate);
+            var unexcusedDays = rows.Count(row => row.IsUnexcused && !row.IsLate);
+            if (unexcusedDays >= 2)
+                PatternNotices.Add(new ClassTeacherPatternNotice(displayName,
+                    $"{unexcusedDays} unentschuldigte Fehltage in 7 Tagen", ClassTeacherStatusKind.Danger));
+            else if (lateDays >= 2)
+                PatternNotices.Add(new ClassTeacherPatternNotice(displayName,
+                    $"{lateDays}-mal verspätet in 7 Tagen", ClassTeacherStatusKind.Warning));
+        }
+        OnPropertyChanged(nameof(HasPatternNotices));
+    }
+
+    /// Erweiterte Mustererkennung (Nutzer-Feedback): die obigen Regeln schauen nur auf die letzten
+    /// 7 Tage und nur auf unentschuldigt/verspätet. Ein Wochentags-Schwerpunkt über einen längeren
+    /// Zeitraum (z.B. "immer montags") ist ein eigenes, oft erst über mehrere Wochen sichtbares
+    /// Signal — deshalb mit den seit Schuljahresbeginn geladenen Daten, nicht nur den letzten 7
+    /// Tagen. Wer schon eine Notiz aus <see cref="BuildPatternNotices"/> hat, wird hier
+    /// ausgelassen, damit die Liste nicht zwei Hinweise für dieselbe Person zeigt.
+    private void BuildWeekdayPatternNotices(IReadOnlyList<ClassAbsenceDaySummaryRow> absenceDays)
+    {
+        var displayNames = Roster.GroupBy(r => UntisNameMatching.NameKey(r.StudentName))
+            .ToDictionary(g => g.Key, g => g.First().StudentName);
+        var alreadyNoted = PatternNotices.Select(n => n.StudentName).ToHashSet();
+        foreach (var notice in DetectWeekdayPatterns(absenceDays, displayNames, alreadyNoted))
+            PatternNotices.Add(notice);
+        OnPropertyChanged(nameof(HasPatternNotices));
+    }
+
+    /// Reine, ohne ViewModel-Zustand testbare Kernlogik (gleiches Muster wie
+    /// <see cref="ClassTeacherRosterRow.Build"/>). <paramref name="minSampleSize"/> verhindert,
+    /// dass zwei zufällig auf denselben Wochentag fallende Fehltage schon als "Muster" gelten;
+    /// <paramref name="clusterThreshold"/> verlangt eine deutliche Häufung, nicht nur eine leichte
+    /// Mehrheit.
+    public static IReadOnlyList<ClassTeacherPatternNotice> DetectWeekdayPatterns(
+        IReadOnlyList<ClassAbsenceDaySummaryRow> absenceDays,
+        IReadOnlyDictionary<string, string> displayNamesByKey,
+        ISet<string> excludeDisplayNames,
+        int minSampleSize = 3, double clusterThreshold = 0.6)
+    {
+        var notices = new List<ClassTeacherPatternNotice>();
+        foreach (var group in absenceDays.GroupBy(row => UntisNameMatching.NameKey(row.StudentName)))
+        {
+            var rows = group.ToList();
+            if (rows.Count < minSampleSize) continue;
+            var displayName = displayNamesByKey.GetValueOrDefault(group.Key) ?? rows[0].StudentDisplayName;
+            if (excludeDisplayNames.Contains(displayName)) continue;
+
+            var top = rows.GroupBy(r => r.Date.DayOfWeek)
+                .Select(g => (Day: g.Key, Count: g.Count()))
+                .OrderByDescending(g => g.Count).First();
+            if ((double)top.Count / rows.Count < clusterThreshold) continue;
+
+            notices.Add(new ClassTeacherPatternNotice(displayName,
+                $"{top.Count} von {rows.Count} Fehltagen an einem {WeekdayLabel(top.Day)}",
+                ClassTeacherStatusKind.Info));
+        }
+        return notices;
+    }
+
+    /// Nutzer-Feedback: "Hohe Fehlquote bei gleichzeitig fallender Mitarbeit ist ein Signal, das
+    /// WebUntis allein nicht liefert." Verknüpft die ohnehin geladene Jahresfehlquote
+    /// (<see cref="ClassTeacherRosterRow.YearAbsenceRatePercent"/>) mit dem Mitarbeit-Trend aus
+    /// dem Dokumentations-/Mitarbeitsmodul (<see cref="IParticipationRepository"/>, gruppen-
+    /// übergreifend über <c>GetByStudent</c>, gleiches Muster wie die Fehlzeitenbilanz in
+    /// StudentDetailViewModel). Bewusst zurückhaltend: nur bei bereits spürbar erhöhter Fehlquote
+    /// UND eindeutig fallendem Trend (erste vs. zweite Hälfte der letzten Bewertungen, gleiche
+    /// simple Heuristik wie <c>ParticipationGradeRow.ComputeTrend</c>), sonst würde die Liste bei
+    /// jeder kleinen Schwankung anschlagen. Reine Beobachtung, keine Kausalitätsaussage — deshalb
+    /// als neutraler Hinweis (Info), nicht als Warnung/Gefahr. Die WebUntis-Rohbewertungen werden
+    /// hier bewusst NICHT nach Aspekt-Gewichtung normiert (anders als in ParticipationGradeRow):
+    /// die Aspekt-Definitionen sind je Lerngruppe konfigurierbar, der Klassenlehrer-Bereich kennt
+    /// aber keine einzelne Gruppe — ein einfacher Rohwert-Durchschnitt über alle Bewertungen ist
+    /// hier die pragmatischere Näherung als ein Konfigurations-Mismatch zu riskieren.
+    private const int CorrelationAbsenceRateThreshold = 15;
+    private void BuildAttendanceParticipationNotices()
+    {
+        var students = _students.GetAll();
+        foreach (var row in Roster.Where(r => r.HasYearSummary &&
+                     r.YearAbsenceRatePercent >= CorrelationAbsenceRateThreshold))
+        {
+            if (PatternNotices.Any(n => n.StudentName == row.StudentName)) continue;
+            var student = MatchStudent(row.StudentName, students);
+            if (student is null) continue;
+
+            var points = _participation.GetByStudent(student.Id)
+                .Select(e => (Session: _participationSessions.GetById(e.SessionId), Entry: e))
+                .Where(x => x.Session is not null && x.Entry.Ratings.Count > 0)
+                .OrderBy(x => x.Session!.Date)
+                .TakeLast(8)
+                .Select(x => x.Entry.Ratings.Average(r => r.Value))
+                .ToList();
+            if (points.Count < 4) continue;
+
+            var mid = points.Count / 2;
+            var diff = points.Skip(mid).Average() - points.Take(mid).Average();
+            if (diff <= -0.4)
+                PatternNotices.Add(new ClassTeacherPatternNotice(row.StudentName,
+                    $"{row.YearAbsenceRatePercent} % Fehlzeit seit Schuljahresbeginn, dabei zuletzt sinkende Mitarbeit",
+                    ClassTeacherStatusKind.Info));
+        }
+        OnPropertyChanged(nameof(HasPatternNotices));
+    }
+
+    /// Reine, ohne Repository-Zugriff testbare Zuordnungslogik. Nutzt <c>FirstName</c>/<c>LastName</c>
+    /// statt <see cref="Student.FullName"/>, weil dessen "Nachname, Vorname"-Format mit Komma den
+    /// leerzeichenbasierten Wortabgleich in <see cref="UntisNameMatching"/> verfälschen würde
+    /// ("Müller," bliebe ein eigenes Wort statt mit "Müller" aus dem WebUntis-Namen zu matchen).
+    public static Student? MatchStudent(string webUntisDisplayName, IReadOnlyList<Student> students)
+    {
+        var key = UntisNameMatching.NameKey(webUntisDisplayName);
+        return students.FirstOrDefault(s => UntisNameMatching.NameKey($"{s.FirstName} {s.LastName}") == key);
+    }
+
+    private static string WeekdayLabel(DayOfWeek day) => day switch
+    {
+        DayOfWeek.Monday => "Montag",
+        DayOfWeek.Tuesday => "Dienstag",
+        DayOfWeek.Wednesday => "Mittwoch",
+        DayOfWeek.Thursday => "Donnerstag",
+        DayOfWeek.Friday => "Freitag",
+        DayOfWeek.Saturday => "Samstag",
+        _ => "Sonntag",
+    };
+
+    /// Zeigt höchstens <see cref="OpenExcuseDisplayLimit"/> Zeilen — Nutzer-Feedback zu den
+    /// anderen Seitenpanels: eine lange Liste soll nicht die ganze Spalte einnehmen. Der Rest
+    /// zählt in <see cref="OpenExcuseOverflowCount"/> und wird als "+N weitere" angezeigt.
+    private const int OpenExcuseDisplayLimit = 6;
+
+    private void BuildOpenExcuses(IReadOnlyList<ClassAbsenceDaySummaryRow> absenceDays, DateOnly today)
+    {
+        var all = ClassTeacherOpenExcuseRow.Build(absenceDays, today);
+        foreach (var row in all.Take(OpenExcuseDisplayLimit)) OpenExcuses.Add(row);
+        OpenExcuseOverflowCount = Math.Max(0, all.Count - OpenExcuseDisplayLimit);
+    }
+
+    [RelayCommand]
+    private void ShowDetailsForOpenExcuse(ClassTeacherOpenExcuseRow? row)
+    {
+        if (row is null) return;
+        DetailsTab.StudentFilter = row.StudentName;
+        ActiveTabIndex = 2;
+        DetailsTab.LoadCommand.Execute(null);
+    }
+
+    /// Nutzer-Feedback: "Aufgaben & Wiedervorlagen öffnen" führt nur ins Modul, das eigentliche
+    /// Erstellen ("Eltern anrufen – Ada Müller") musste man dort noch einmal von Hand eintippen.
+    /// Legt direkt eine Wiedervorlage an (Kind=Reminder, wie 6.1.1) statt einen Dialog zu öffnen —
+    /// der bearbeitet sie bei Bedarf im Aufgaben-Modul weiter, wo `OnEditTask` (siehe
+    /// WorkTaskListView) ohnehin nur dort verdrahtet ist. Bewusst ohne GroupId: Klassenlehrer ist
+    /// man für die ganze Klasse, nicht für einen einzelnen Kurs (siehe Klassendoku oben).
+    [RelayCommand]
+    private void CreateReminderForStudent(ClassTeacherRosterRow? row)
+    {
+        if (row is null) return;
+        SaveReminder(row.StudentName, row.StatusText, urgent: row.IsUnexcused);
+    }
+
+    [RelayCommand]
+    private void CreateReminderForOpenExcuse(ClassTeacherOpenExcuseRow? row)
+    {
+        if (row is null) return;
+        SaveReminder(row.StudentName, $"{row.DaysOpenLabel} (Fehltag vom {row.DateLabel}).",
+            urgent: row.IsOverdue);
+    }
+
+    private void SaveReminder(string studentName, string notes, bool urgent)
+    {
+        var task = new WorkTask
+        {
+            Title = $"Eltern kontaktieren – {studentName}",
+            Notes = notes,
+            Kind = TaskKind.Reminder,
+            Priority = urgent ? TaskPriority.High : TaskPriority.Normal,
+            DueDate = DateOnly.FromDateTime(DateTime.Today).AddDays(1),
+        };
+        _workTasks.Save(task);
+        Status = $"Wiedervorlage „{task.Title}\" angelegt — zu finden unter Aufgaben & Wiedervorlagen.";
+    }
+
+    private int Percent(int value) => StudentCount == 0 ? 0 : (int)Math.Round(100d * value / StudentCount);
+    private void NotifySummary()
+    {
+        OnPropertyChanged(nameof(TodayUnexcusedPercent)); OnPropertyChanged(nameof(LatePercent));
+        OnPropertyChanged(nameof(PresentPercent)); OnPropertyChanged(nameof(ExcusedAbsencePercent));
+        OnPropertyChanged(nameof(UnexcusedAbsencePercent));
+        OnPropertyChanged(nameof(TodayUnexcusedSummaryLabel));
+        OnPropertyChanged(nameof(PresentSummaryLabel)); OnPropertyChanged(nameof(LateSummaryLabel));
+        OnPropertyChanged(nameof(ExcusedAbsenceSummaryLabel)); OnPropertyChanged(nameof(UnexcusedAbsenceSummaryLabel));
+        OnPropertyChanged(nameof(PresentFraction)); OnPropertyChanged(nameof(LateFraction));
+        OnPropertyChanged(nameof(ExcusedAbsenceFraction)); OnPropertyChanged(nameof(UnexcusedAbsenceFraction));
+        OnPropertyChanged(nameof(DayOverviewTooltip));
+    }
+    private void NotifyRosterState()
+    {
+        OnPropertyChanged(nameof(HasPrimaryRoster)); OnPropertyChanged(nameof(HasSecondaryRoster));
+        OnPropertyChanged(nameof(HasNoFilterResults)); OnPropertyChanged(nameof(HasOpenExcuses));
+    }
+}

LehrerApp.Desktop/ViewModels/ClassTeacher/UntisNameMatching.cs

@@ -0,0 +1,22 @@
+namespace LehrerApp.Desktop.ViewModels.ClassTeacher;
+
+/// <summary>
+/// WebUntis liefert Schülernamen je nach Bericht in unterschiedlicher Reihenfolge — der
+/// Schülerreport baut "Vorname Nachname" (<see cref="Services.UntisStudentDto.DisplayName"/>),
+/// die Fehlzeiten-/Klassenbuchberichte liefern typischerweise "Nachname Vorname". Ein exakter
+/// String-Vergleich zwischen diesen Quellen schlägt deshalb praktisch immer fehl (Bug: gefilterte
+/// Listen im Klassenlehrer-Bereich blieben leer, Roster-Symbole waren durchgängig falsch). Der
+/// Vergleich hier ist deshalb reihenfolge-unabhängig: beide Namen werden in Wörter zerlegt und als
+/// sortierte Menge verglichen (kein Abgleich über eine externe Schülerkennung möglich, da der
+/// Klassenbuch-Bericht keine liefert, siehe UntisForeignClassRegisterEventDto).
+/// </summary>
+public static class UntisNameMatching
+{
+    public static bool NamesMatch(string? a, string? b) =>
+        !string.IsNullOrWhiteSpace(a) && !string.IsNullOrWhiteSpace(b) && NameKey(a) == NameKey(b);
+
+    public static string NameKey(string value) => string.Join(' ',
+        value.Split(' ', StringSplitOptions.RemoveEmptyEntries)
+            .Select(w => w.Trim().ToLowerInvariant())
+            .OrderBy(w => w, StringComparer.Ordinal));
+}

LehrerApp.Desktop/ViewModels/DashboardViewModel.cs

@@ -107,6 +107,15 @@ public partial class DashboardViewModel : ObservableObject
     public DashboardCardOption AttendanceCard => Card("attendance");
     public DashboardCardOption SupportCard => Card("support");
     public DashboardCardOption GroupsCard => Card("groups");
+    public int TodayLessonCount => TodaysLessons.Count;
+    public int OpenTaskCount => OpenTasks.Count;
+    public int UpcomingCount => UpcomingDates.Count;
+    public int AttentionCount => OpenExcuses.Count + AttendanceWarnings.Count + SupportPlanReviews.Count
+        + OpenCorrections.Count + UnplannedLessons.Count + Alerts.Count;
+    public string TodayLessonSummary => TodayLessonCount == 1 ? "1 Stunde" : $"{TodayLessonCount} Stunden";
+    public string OpenTaskSummary => OpenTaskCount == 1 ? "1 Aufgabe" : $"{OpenTaskCount} Aufgaben";
+    public string AttentionSummary => AttentionCount == 1 ? "1 offener Punkt" : $"{AttentionCount} offene Punkte";
+    public string UpcomingSummary => UpcomingCount == 1 ? "1 Termin" : $"{UpcomingCount} Termine";
 
     public DashboardViewModel(IGroupRepository groups, ISubjectRepository subjects, ILessonRepository lessons,
         IExamRepository exams, IExamResultRepository examResults, IGradeRepository grades,
@@ -204,6 +213,31 @@ public partial class DashboardViewModel : ObservableObject
         LoadOpenCorrections(groups, today);
         LoadUnplannedLessons(groups, today);
         LoadAlerts(groups, today);
+        UpdateDashboardSummary();
+    }
+
+    private void UpdateDashboardSummary()
+    {
+        TodayCard.IsEmpty = TodaysLessons.Count == 0;
+        TasksCard.IsEmpty = OpenTasks.Count == 0;
+        CalendarCard.IsEmpty = false;
+        ExcusesCard.IsEmpty = OpenExcuses.Count == 0;
+        UpcomingCard.IsEmpty = UpcomingDates.Count == 0;
+        CorrectionsCard.IsEmpty = OpenCorrections.Count == 0;
+        UnplannedCard.IsEmpty = UnplannedLessons.Count == 0;
+        AlertsCard.IsEmpty = Alerts.Count == 0;
+        AttendanceCard.IsEmpty = AttendanceWarnings.Count == 0;
+        SupportCard.IsEmpty = SupportPlanReviews.Count == 0;
+        GroupsCard.IsEmpty = CurrentGroups.Count == 0;
+
+        OnPropertyChanged(nameof(TodayLessonCount));
+        OnPropertyChanged(nameof(OpenTaskCount));
+        OnPropertyChanged(nameof(UpcomingCount));
+        OnPropertyChanged(nameof(AttentionCount));
+        OnPropertyChanged(nameof(TodayLessonSummary));
+        OnPropertyChanged(nameof(OpenTaskSummary));
+        OnPropertyChanged(nameof(AttentionSummary));
+        OnPropertyChanged(nameof(UpcomingSummary));
     }
 
     private async Task LoadWeatherAsync()
@@ -352,12 +386,10 @@ public partial class DashboardViewModel : ObservableObject
                      .Where(e => e.Status is ExamStatus.Conducted or ExamStatus.Graded)
                      .OrderBy(e => e.Date))
         {
-            var expected = _memberships.GetByGroup(group.Id)
+            var (expected, evaluated) = ExamCorrectionCounter.Count(exam,
-                .Count(m => GroupMembershipService.IsActiveOn(m, exam.Date));
+                _memberships.GetByGroup(group.Id), _examResults.GetByExam(exam.Id));
-            var evaluated = _examResults.GetByExam(exam.Id)
-                .Count(r => r.Absent || !string.IsNullOrWhiteSpace(r.Grade) || r.Points.Count > 0);
             OpenCorrections.Add(new CorrectionProgressItem(exam.Id, group.Id, exam.Title,
-                group.Name, exam.Date, Math.Min(evaluated, expected), expected, today));
+                group.Name, exam.Date, evaluated, expected, today));
         }
     }
 
@@ -592,6 +624,7 @@ public partial class DashboardViewModel : ObservableObject
         entry.Attendance = status;
         _participationEntries.Save(entry);
         OpenExcuses.Remove(item);
+        UpdateDashboardSummary();
     }
 
     private void LoadCalendar()
@@ -1034,18 +1067,29 @@ public sealed class DashboardAlertItem(Guid studentId, Guid? groupId, string stu
 public partial class DashboardCardOption : ObservableObject
 {
     [ObservableProperty] private bool _isVisible;
+    [ObservableProperty] private bool _isEmpty;
     [ObservableProperty] private int _row;
     [ObservableProperty] private int _column;
     public string Key { get; }
     public string Title { get; }
+    public bool HideWhenEmpty { get; }
+    public bool EffectiveIsVisible => IsVisible && (!HideWhenEmpty || !IsEmpty);
     public Action? OnVisibilityChanged { get; set; }
 
     public DashboardCardOption(string key, string title, bool isVisible)
     {
         Key = key;
         Title = title;
+        HideWhenEmpty = key is "excuses" or "upcoming" or "corrections" or "unplanned"
+            or "alerts" or "attendance" or "support";
         _isVisible = isVisible;
     }
 
-    partial void OnIsVisibleChanged(bool value) => OnVisibilityChanged?.Invoke();
+    partial void OnIsVisibleChanged(bool value)
+    {
+        OnPropertyChanged(nameof(EffectiveIsVisible));
+        OnVisibilityChanged?.Invoke();
+    }
+
+    partial void OnIsEmptyChanged(bool value) => OnPropertyChanged(nameof(EffectiveIsVisible));
 }

LehrerApp.Desktop/ViewModels/Exams/ExamsOverviewViewModel.cs

@@ -0,0 +1,253 @@
+using CommunityToolkit.Mvvm.ComponentModel;
+using CommunityToolkit.Mvvm.Input;
+using LehrerApp.Core.Interfaces;
+using LehrerApp.Core.Models;
+using LehrerApp.Core.Services;
+using LehrerApp.Desktop.ViewModels.Groups;
+using System.Collections.ObjectModel;
+using System.Globalization;
+
+namespace LehrerApp.Desktop.ViewModels.Exams;
+
+/// Klausuren-Hauptseite (Sidebar "Klausuren"): gruppenübergreifende Liste aller Klausuren des
+/// aktuellen Schuljahres, sortiert nach einem unsichtbaren Prioritäts-Score
+/// (`ExamPriorityService`) statt nach Datum — unbearbeitete/überfällige Korrekturen oben,
+/// erledigte unten. Oben ein Detailbereich zur ausgewählten Klausur, der sich je nach Status
+/// unterscheidet (Korrekturfortschritt vs. Notenspiegel), inklusive Umschalter für Parallelkurse
+/// (gleiche Arbeit, mehrere Kurse — siehe `Exam.SharedExamGroupId`).
+public partial class ExamsOverviewViewModel : ObservableObject
+{
+    private readonly IExamRepository _exams;
+    private readonly IExamResultRepository _examResults;
+    private readonly IGroupRepository _groups;
+    private readonly IGroupMembershipRepository _memberships;
+    private readonly GradingService _grading;
+    private readonly SchoolYearService _schoolYear;
+
+    public ObservableCollection<ExamListRowViewModel> Rows { get; } = [];
+    public ObservableCollection<ExamListRowViewModel> Siblings { get; } = [];
+    public ObservableCollection<GradeBarItem> DetailGradeDistribution { get; } = [];
+
+    [ObservableProperty] private ExamListRowViewModel? _selectedRow;
+    [ObservableProperty] private bool _hasSelection;
+    [ObservableProperty] private string _emptyHint = "";
+
+    [ObservableProperty] private bool _showCorrectionProgress;
+    [ObservableProperty] private string _progressLabel = "";
+    [ObservableProperty] private double _progressBarWidth;
+    [ObservableProperty] private bool _showGradeSummary;
+    [ObservableProperty] private string _averageLabel = "";
+    [ObservableProperty] private string _approvalLabel = "";
+    [ObservableProperty] private string _announcementLabel = "";
+
+    public Func<Exam, Task>? OnGradeExam { get; set; }
+    public Func<Exam, Task>? OnEvaluateExam { get; set; }
+    public Action<Guid>? OnNavigateToGroup { get; set; }
+
+    public ExamsOverviewViewModel(IExamRepository exams, IExamResultRepository examResults,
+        IGroupRepository groups, IGroupMembershipRepository memberships, GradingService grading,
+        SchoolYearService schoolYear)
+    {
+        _exams = exams; _examResults = examResults; _groups = groups;
+        _memberships = memberships; _grading = grading; _schoolYear = schoolYear;
+    }
+
+    [RelayCommand]
+    public void Load()
+    {
+        var selectedId = SelectedRow?.Exam.Id;
+        Rows.Clear();
+
+        var groups = _groups.GetBySchoolYear(_schoolYear.CurrentSchoolYear());
+        var today = DateOnly.FromDateTime(DateTime.Today);
+
+        var rows = new List<ExamListRowViewModel>();
+        foreach (var group in groups)
+        {
+            var groupMemberships = _memberships.GetByGroup(group.Id);
+            foreach (var exam in _exams.GetByGroup(group.Id))
+            {
+                var (expected, evaluated) = ExamCorrectionCounter.Count(exam, groupMemberships,
+                    _examResults.GetByExam(exam.Id));
+                var info = ExamPriorityService.Evaluate(exam, expected, evaluated, today);
+                rows.Add(new ExamListRowViewModel(exam, group, expected, evaluated, info, today));
+            }
+        }
+
+        // Parallelkurse markieren, damit die Liste einen Verknüpfungs-Hinweis zeigen kann.
+        foreach (var group in rows.GroupBy(r => r.Exam.SharedExamGroupId ?? r.Exam.Id))
+        {
+            if (group.Count() <= 1) continue;
+            foreach (var row in group) row.HasSibling = true;
+        }
+
+        foreach (var row in rows.OrderByDescending(r => r.Score))
+            Rows.Add(row);
+
+        EmptyHint = Rows.Count == 0 ? "Keine Klausuren angelegt." : "";
+        SelectedRow = selectedId is { } id
+            ? Rows.FirstOrDefault(r => r.Exam.Id == id) ?? Rows.FirstOrDefault()
+            : Rows.FirstOrDefault();
+    }
+
+    partial void OnSelectedRowChanged(ExamListRowViewModel? value) => UpdateDetail(value);
+
+    private void UpdateDetail(ExamListRowViewModel? row)
+    {
+        HasSelection = row is not null;
+        Siblings.Clear();
+        DetailGradeDistribution.Clear();
+        ShowCorrectionProgress = false;
+        ShowGradeSummary = false;
+        if (row is null) return;
+
+        ApprovalLabel = row.Exam.ApprovalGrantedAt is { } a
+            ? $"Genehmigt am {a.ToString("dd.MM.yyyy", CultureInfo.InvariantCulture)}"
+            : "Genehmigung noch ausstehend";
+        AnnouncementLabel = row.Exam.AnnouncedAt is { } n
+            ? $"Angekündigt am {n.ToString("dd.MM.yyyy", CultureInfo.InvariantCulture)}"
+            : "Noch nicht angekündigt";
+
+        if (row.HasSibling)
+        {
+            var anchor = row.Exam.SharedExamGroupId ?? row.Exam.Id;
+            foreach (var sibling in Rows.Where(r => r != row && (r.Exam.SharedExamGroupId ?? r.Exam.Id) == anchor))
+                Siblings.Add(sibling);
+        }
+
+        ShowCorrectionProgress = row.Status is ExamListStatus.AwaitingCorrection
+            or ExamListStatus.CorrectionInProgress or ExamListStatus.CorrectionStuck;
+        if (ShowCorrectionProgress)
+        {
+            ProgressLabel = $"{row.Evaluated} / {row.Expected} korrigiert";
+            var fraction = row.Expected <= 0 ? 0 : Math.Clamp((double)row.Evaluated / row.Expected, 0, 1);
+            ProgressBarWidth = fraction * 240.0;
+        }
+
+        ShowGradeSummary = row.Status is ExamListStatus.AwaitingReturn or ExamListStatus.Returned;
+        if (ShowGradeSummary) LoadGradeSummary(row);
+    }
+
+    private void LoadGradeSummary(ExamListRowViewModel row)
+    {
+        var grades = _examResults.GetByExam(row.Exam.Id)
+            .Where(r => !r.Absent && !string.IsNullOrWhiteSpace(r.Grade))
+            .Select(r => r.Grade!).ToList();
+        if (grades.Count == 0) { AverageLabel = "Noch keine Noten erfasst."; return; }
+
+        AverageLabel = "Ø " + _grading.WeightedAverage(grades.Select(g => (Grade: g, Weight: 1.0)).ToList())
+            .ToString("0.00", CultureInfo.InvariantCulture);
+
+        var counts = grades.GroupBy(g => g).ToDictionary(g => g.Key, g => g.Count());
+        var maxCount = counts.Count == 0 ? 0 : counts.Values.Max();
+        foreach (var entry in row.Exam.GradingKey.OrderByDescending(e => e.MinPercent))
+        {
+            counts.TryGetValue(entry.Grade, out var count);
+            DetailGradeDistribution.Add(new GradeBarItem(entry.Grade, count, grades.Count, maxCount));
+        }
+    }
+
+    [RelayCommand]
+    private void SelectExam(ExamListRowViewModel row) => SelectedRow = row;
+
+    [RelayCommand]
+    private async Task GradeSelected()
+    {
+        if (SelectedRow is null || OnGradeExam is null) return;
+        await OnGradeExam(SelectedRow.Exam);
+        Load();
+    }
+
+    [RelayCommand]
+    private async Task EvaluateSelected()
+    {
+        if (SelectedRow is null || OnEvaluateExam is null) return;
+        await OnEvaluateExam(SelectedRow.Exam);
+        Load();
+    }
+
+    [RelayCommand]
+    private void GoToGroup()
+    {
+        if (SelectedRow is null) return;
+        OnNavigateToGroup?.Invoke(SelectedRow.GroupId);
+    }
+
+    [RelayCommand]
+    private void ToggleApproval() => ToggleDate(SelectedRow?.Exam, e => e.ApprovalGrantedAt,
+        (e, v) => e.ApprovalGrantedAt = v);
+
+    [RelayCommand]
+    private void ToggleAnnouncement() => ToggleDate(SelectedRow?.Exam, e => e.AnnouncedAt,
+        (e, v) => e.AnnouncedAt = v);
+
+    private void ToggleDate(Exam? exam, Func<Exam, DateOnly?> get, Action<Exam, DateOnly?> set)
+    {
+        if (exam is null) return;
+        set(exam, get(exam) is null ? DateOnly.FromDateTime(DateTime.Today) : null);
+        exam.UpdatedAt = DateTime.UtcNow;
+        _exams.Save(exam);
+        UpdateDetail(SelectedRow);
+    }
+}
+
+// ── Zeile in der Klausurliste ────────────────────────────────────────────────
+
+public class ExamListRowViewModel
+{
+    public Exam Exam { get; }
+    public Guid GroupId { get; }
+    public string Title { get; }
+    public string GroupLabel { get; }
+    public int Expected { get; }
+    public int Evaluated { get; }
+    public ExamListStatus Status { get; }
+    public double Score { get; }
+    public string StatusLabel { get; }
+    public string SubLabel { get; }
+    public bool HasSibling { get; set; }
+
+    public bool IsOk { get; }
+    public bool IsInfo { get; }
+    public bool IsWarning { get; }
+    public bool IsDanger { get; }
+
+    public ExamListRowViewModel(Exam exam, LearningGroup group, int expected, int evaluated,
+        ExamPriorityInfo info, DateOnly today)
+    {
+        Exam = exam; GroupId = group.Id; Title = exam.Title; GroupLabel = group.Name;
+        Expected = expected; Evaluated = evaluated; Status = info.Status; Score = info.Score;
+
+        (StatusLabel, SubLabel, IsOk, IsInfo, IsWarning, IsDanger) = Status switch
+        {
+            ExamListStatus.Planned => ("Geplant", $"geplant für {RelativeDay(exam.Date, today)}",
+                false, false, false, false),
+            ExamListStatus.AwaitingCorrection when today.DayNumber - exam.Date.DayNumber <= 3 =>
+                ("Korrektur ausstehend", $"geschrieben {RelativeDay(exam.Date, today)}",
+                    false, false, true, false),
+            ExamListStatus.AwaitingCorrection =>
+                ("überfällig", $"geschrieben {RelativeDay(exam.Date, today)}", false, false, false, true),
+            ExamListStatus.CorrectionInProgress =>
+                ("Korrektur läuft", $"{evaluated}/{expected} korrigiert", false, false, true, false),
+            ExamListStatus.CorrectionStuck =>
+                ("hängt fest", $"{evaluated}/{expected} korrigiert", false, false, false, false),
+            ExamListStatus.AwaitingReturn => ("Korrigiert", "Rückgabe aussteht", false, true, false, false),
+            ExamListStatus.Returned => ("Abgeschlossen",
+                exam.ReturnedAt is { } r ? $"zurückgegeben {r:dd.MM.yyyy}" : "zurückgegeben", true, false, false, false),
+            _ => ("", "", false, false, false, false),
+        };
+    }
+
+    private static string RelativeDay(DateOnly date, DateOnly today)
+    {
+        var diff = date.DayNumber - today.DayNumber;
+        return diff switch
+        {
+            0 => "heute",
+            1 => "morgen",
+            -1 => "gestern",
+            > 1 => $"in {diff} Tagen",
+            _ => $"vor {-diff} Tagen",
+        };
+    }
+}

LehrerApp.Desktop/ViewModels/GlobalSearchViewModel.cs

@@ -0,0 +1,194 @@
+using CommunityToolkit.Mvvm.ComponentModel;
+using CommunityToolkit.Mvvm.Input;
+using LehrerApp.Core.Interfaces;
+using LehrerApp.Core.Models;
+using System.Collections.ObjectModel;
+
+namespace LehrerApp.Desktop.ViewModels;
+
+/// <summary>
+/// Globale Suche und Schnellerfassung (14.2). Die Projektion bleibt bewusst klein und lokal:
+/// durchsucht werden die wichtigsten täglichen Ziele, ohne dafür einen zusätzlichen Suchindex
+/// oder eine Netzwerkabhängigkeit einzuführen.
+/// </summary>
+public partial class GlobalSearchViewModel : ObservableObject
+{
+    private const int MaxDataResults = 12;
+
+    private readonly IStudentRepository _students;
+    private readonly IGroupRepository _groups;
+    private readonly IExamRepository _exams;
+    private readonly IWorkTaskRepository _tasks;
+
+    [ObservableProperty] private string _query = "";
+    [ObservableProperty] private GlobalSearchResult? _selectedResult;
+
+    public ObservableCollection<GlobalSearchResult> Results { get; } = [];
+    public bool HasResults => Results.Count > 0;
+    public bool ShowNoResults => !string.IsNullOrWhiteSpace(Query) && Results.Count == 0;
+
+    public Action<GlobalSearchResult>? OnNavigate { get; set; }
+    public Func<bool, Task>? OnQuickAddTask { get; set; }
+    public Func<Task>? OnQuickAddStudent { get; set; }
+    public Action? OnClose { get; set; }
+
+    public GlobalSearchViewModel(IStudentRepository students, IGroupRepository groups,
+        IExamRepository exams, IWorkTaskRepository tasks)
+    {
+        _students = students;
+        _groups = groups;
+        _exams = exams;
+        _tasks = tasks;
+        RefreshResults();
+    }
+
+    partial void OnQueryChanged(string value) => RefreshResults();
+
+    public void Reset()
+    {
+        Query = "";
+        RefreshResults();
+    }
+
+    private void RefreshResults()
+    {
+        Results.Clear();
+        var query = Query.Trim();
+
+        AddQuickActions(query);
+
+        if (query.Length > 0)
+        {
+            var groups = _groups.GetAll(includeInactive: true);
+            var groupNames = groups.ToDictionary(g => g.Id, g => g.Name);
+            var candidates = new List<GlobalSearchResult>();
+
+            candidates.AddRange(_students.GetAll(includeInactive: true)
+                .Where(s => Matches(s.FullName, query))
+                .Select(s => GlobalSearchResult.ForStudent(s)));
+
+            candidates.AddRange(groups
+                .Where(g => Matches($"{g.Name} {g.SchoolYear} {g.GradeLevel}", query))
+                .Select(GlobalSearchResult.ForGroup));
+
+            candidates.AddRange(_exams.GetAll()
+                .Where(e => Matches($"{e.Title} {groupNames.GetValueOrDefault(e.GroupId)}", query))
+                .Select(e => GlobalSearchResult.ForExam(e, groupNames.GetValueOrDefault(e.GroupId) ?? "")));
+
+            candidates.AddRange(_tasks.GetAll()
+                .Where(t => Matches($"{t.Title} {t.Notes} {groupNames.GetValueOrDefault(t.GroupId ?? Guid.Empty)}", query))
+                .Select(t => GlobalSearchResult.ForTask(t, groupNames.GetValueOrDefault(t.GroupId ?? Guid.Empty) ?? "")));
+
+            foreach (var item in candidates
+                         .OrderByDescending(x => x.Title.StartsWith(query, StringComparison.CurrentCultureIgnoreCase))
+                         .ThenBy(x => x.KindSortOrder)
+                         .ThenBy(x => x.Title)
+                         .Take(MaxDataResults))
+                Results.Add(item);
+        }
+
+        SelectedResult = Results.FirstOrDefault();
+        OnPropertyChanged(nameof(HasResults));
+        OnPropertyChanged(nameof(ShowNoResults));
+    }
+
+    private void AddQuickActions(string query)
+    {
+        var actions = new[]
+        {
+            GlobalSearchResult.ForAction(GlobalSearchAction.NewTask, "Aufgabe anlegen", "Mit Fälligkeit, Gruppe und Priorität", "＋"),
+            GlobalSearchResult.ForAction(GlobalSearchAction.NewReminder, "Erinnerung anlegen", "Kurze Notiz ohne Zeiterfassung", "◷"),
+            GlobalSearchResult.ForAction(GlobalSearchAction.NewStudent, "Schüler anlegen", "Neue Stammdaten erfassen", "＋"),
+        };
+
+        foreach (var action in actions.Where(a => query.Length == 0 || Matches(a.Title, query)))
+            Results.Add(action);
+    }
+
+    private static bool Matches(string? value, string query) =>
+        value?.Contains(query, StringComparison.CurrentCultureIgnoreCase) == true;
+
+    [RelayCommand]
+    private async Task Execute(GlobalSearchResult? result)
+    {
+        if (result is null) return;
+
+        switch (result.Action)
+        {
+            case GlobalSearchAction.NewTask:
+                if (OnQuickAddTask is not null) await OnQuickAddTask(false);
+                break;
+            case GlobalSearchAction.NewReminder:
+                if (OnQuickAddTask is not null) await OnQuickAddTask(true);
+                break;
+            case GlobalSearchAction.NewStudent:
+                if (OnQuickAddStudent is not null) await OnQuickAddStudent();
+                break;
+            default:
+                OnNavigate?.Invoke(result);
+                break;
+        }
+
+        OnClose?.Invoke();
+    }
+}
+
+public enum GlobalSearchResultKind { Action, Student, Group, Exam, Task }
+public enum GlobalSearchAction { None, NewTask, NewReminder, NewStudent }
+
+public sealed class GlobalSearchResult
+{
+    public GlobalSearchResultKind Kind { get; private init; }
+    public GlobalSearchAction Action { get; private init; }
+    public Guid? EntityId { get; private init; }
+    public Guid? GroupId { get; private init; }
+    public string Title { get; private init; } = "";
+    public string Subtitle { get; private init; } = "";
+    public string Icon { get; private init; } = "";
+    public int KindSortOrder => Kind switch
+    {
+        GlobalSearchResultKind.Student => 0,
+        GlobalSearchResultKind.Group => 1,
+        GlobalSearchResultKind.Exam => 2,
+        GlobalSearchResultKind.Task => 3,
+        _ => -1,
+    };
+    public string KindLabel => Kind switch
+    {
+        GlobalSearchResultKind.Student => "Schüler",
+        GlobalSearchResultKind.Group => "Lerngruppe",
+        GlobalSearchResultKind.Exam => "Klausur",
+        GlobalSearchResultKind.Task => "Aufgabe",
+        _ => "Schnellaktion",
+    };
+
+    public static GlobalSearchResult ForAction(GlobalSearchAction action, string title, string subtitle, string icon) =>
+        new() { Kind = GlobalSearchResultKind.Action, Action = action, Title = title, Subtitle = subtitle, Icon = icon };
+
+    public static GlobalSearchResult ForStudent(Student student) => new()
+    {
+        Kind = GlobalSearchResultKind.Student, EntityId = student.Id,
+        Title = student.FullName, Subtitle = student.IsActive ? "Aktiv" : "Inaktiv", Icon = "P",
+    };
+
+    public static GlobalSearchResult ForGroup(LearningGroup group) => new()
+    {
+        Kind = GlobalSearchResultKind.Group, EntityId = group.Id, GroupId = group.Id,
+        Title = group.Name, Subtitle = $"{group.SchoolYear} · Stufe {group.GradeLevel}", Icon = "G",
+    };
+
+    public static GlobalSearchResult ForExam(Exam exam, string groupName) => new()
+    {
+        Kind = GlobalSearchResultKind.Exam, EntityId = exam.Id, GroupId = exam.GroupId,
+        Title = exam.Title, Subtitle = $"{groupName} · {exam.Date:dd.MM.yyyy}", Icon = "K",
+    };
+
+    public static GlobalSearchResult ForTask(WorkTask task, string groupName) => new()
+    {
+        Kind = GlobalSearchResultKind.Task, EntityId = task.Id, GroupId = task.GroupId,
+        Title = task.Title,
+        Subtitle = string.Join(" · ", new[] { groupName, task.DueDate?.ToString("dd.MM.yyyy") ?? "" }
+            .Where(x => !string.IsNullOrWhiteSpace(x))),
+        Icon = task.Kind == TaskKind.Reminder ? "E" : "A",
+    };
+}

LehrerApp.Desktop/ViewModels/Groups/ExamGradingViewModels.cs

@@ -1,4 +1,5 @@
 using CommunityToolkit.Mvvm.ComponentModel;
+using CommunityToolkit.Mvvm.Input;
 using LehrerApp.Core.Interfaces;
 using LehrerApp.Core.Models;
 using LehrerApp.Core.Services;
@@ -52,6 +53,16 @@ public partial class ExamGradingDialogViewModel : ObservableObject
 
     private void SaveRow(ExamResultRow row) => _results.Save(row.ToModel(_exam.Id));
 
+    /// Rest als abwesend markieren (Nutzerwunsch): Schüler, die nie nachschreiben, blockieren
+    /// sonst dauerhaft den live abgeleiteten Korrekturstatus (ExamPriorityService), weil niemand
+    /// eine leere Zeile anfasst, für die es nichts einzutragen gibt. Rührt bewusst nur unberührte
+    /// Zeilen an — bereits eingetragene Punkte/Kommentare bleiben unangetastet.
+    [RelayCommand]
+    private void MarkRemainingAbsent()
+    {
+        foreach (var row in Rows.Where(r => !r.Absent && r.Cells.All(c => c.Value is null)))
+            row.Absent = true;
+    }
 }
 
 // ── Zeile im Punkteraster ──────────────────────────────────────────────────

LehrerApp.Desktop/ViewModels/Groups/ExamViewModels.cs

@@ -21,6 +21,7 @@ public partial class ExamDialogViewModel : ObservableObject
     private readonly int _gradeLevel;
     private readonly GradingSystem _gradingSystem;
     private readonly Exam? _editingExam;
+    private readonly Exam? _duplicateSource;
     private readonly string _subjectName;
 
     [ObservableProperty] private string _title = "";
@@ -68,6 +69,7 @@ public partial class ExamDialogViewModel : ObservableObject
         _groupId = groupId; _subjectId = subjectId; _gradeLevel = gradeLevel;
         _gradingSystem = gradingSystem;
         _editingExam = editingExam;
+        _duplicateSource = duplicateSource;
         _subjectName = defaultSubjectName;
         IsDifferentiated = isDifferentiated;
 
@@ -304,6 +306,11 @@ public partial class ExamDialogViewModel : ObservableObject
         Result.Niveau     = NiveauDisplay.FromName(SelectedNiveauName);
         Result.Tasks      = Tasks.Select(t => t.ToModel()).ToList();
         Result.GradingKey = gradingKey;
+        // Parallelkurse (gleiche Arbeit, mehrere Kurse): beim Duplizieren verknüpfen, damit die
+        // Klausuren-Hauptseite zwischen ihnen umschalten kann. Der Anker ist die Id der zuerst
+        // angelegten Klausur der Kette — schon verknüpfte Quellen geben ihren Anker weiter.
+        if (_duplicateSource is not null)
+            Result.SharedExamGroupId = _duplicateSource.SharedExamGroupId ?? _duplicateSource.Id;
         _exams.Save(Result);
     }
 }

LehrerApp.Desktop/ViewModels/Groups/GroupViewModels.cs

@@ -13,13 +13,8 @@ namespace LehrerApp.Desktop.ViewModels.Groups;
 
 public partial class GroupListViewModel : ObservableObject
 {
-    private const int QuickTasksMaxCount = 3;
-
     private readonly IGroupRepository _groups;
     private readonly ISubjectRepository _subjects;
-    private readonly ILessonRepository _lessons;
-    private readonly IExamRepository _exams;
-    private readonly IWorkTaskRepository _tasks;
 
     public Action<Guid, int>? OnNavigateToDetail { get; set; }
     public Func<Task>? OnAddGroup { get; set; }
@@ -29,11 +24,8 @@ public partial class GroupListViewModel : ObservableObject
 
     [ObservableProperty] private string _selectedSchoolYear = "";
     [ObservableProperty] private string _searchText = "";
-    [ObservableProperty] private GroupListItem? _selectedGroup;
     [ObservableProperty] private bool _showArchived;
 
-    public string SelectedGroupDisplayName => SelectedGroup?.DisplayName ?? "";
-    public string SelectedGroupSubtitle => SelectedGroup?.Subtitle ?? "";
     public string ListSummary => ShowArchived
         ? $"{Groups.Count} archivierte Gruppen · {SelectedSchoolYear}"
         : $"{Groups.Count} aktive Gruppen · {SelectedSchoolYear}";
@@ -45,22 +37,10 @@ public partial class GroupListViewModel : ObservableObject
     public ObservableCollection<string> SchoolYears { get; } = [];
     public ObservableCollection<GroupListItem> Groups { get; } = [];
 
-    // ── Schnellüberblick im Auswahl-Panel (Nutzer-Feedback: "oberhalb der Buttonliste ein paar
+    public GroupListViewModel(IGroupRepository groups, ISubjectRepository subjects, SchoolYearService sy)
-    // Daten auswerfen. Nächste Stunde, nächste Arbeit, wichtige Todos") — bewusst dieselben
-    // kompakten Kennzahlen wie die obersten Karten des Kurs-Dashboards (GroupOverviewViewModel),
-    // hier nur ohne eigenen Tab-Wechsel, da man ohnehin schon auf der Gruppenliste steht.
-    [ObservableProperty] private bool _quickHasNextLesson;
-    [ObservableProperty] private string _quickNextLessonLabel = "";
-    [ObservableProperty] private bool _quickHasNextExam;
-    [ObservableProperty] private string _quickNextExamLabel = "";
-    public ObservableCollection<GroupTaskItem> QuickTasks { get; } = [];
-    public bool QuickHasTasks => QuickTasks.Count > 0;
-    public bool QuickHasAnything => QuickHasNextLesson || QuickHasNextExam || QuickHasTasks;
-
-    public GroupListViewModel(IGroupRepository groups, ISubjectRepository subjects, SchoolYearService sy,
-        ILessonRepository lessons, IExamRepository exams, IWorkTaskRepository tasks)
     {
-        _groups = groups; _subjects = subjects; _lessons = lessons; _exams = exams; _tasks = tasks;
+        _groups = groups;
+        _subjects = subjects;
         foreach (var y in sy.RecentSchoolYears()) SchoolYears.Add(y);
         SelectedSchoolYear = sy.CurrentSchoolYear();
     }
@@ -68,58 +48,8 @@ public partial class GroupListViewModel : ObservableObject
     partial void OnSelectedSchoolYearChanged(string value) => LoadGroups();
     partial void OnSearchTextChanged(string value)          => LoadGroups();
     partial void OnShowArchivedChanged(bool value)           => LoadGroups();
-    partial void OnSelectedGroupChanged(GroupListItem? value)
-    {
-        OnPropertyChanged(nameof(SelectedGroupDisplayName));
-        OnPropertyChanged(nameof(SelectedGroupSubtitle));
-        NavigateToSectionCommand.NotifyCanExecuteChanged();
-        EditGroupCommand.NotifyCanExecuteChanged();
-        RollOverGroupCommand.NotifyCanExecuteChanged();
-        ToggleArchiveCommand.NotifyCanExecuteChanged();
-        DeleteGroupCommand.NotifyCanExecuteChanged();
-        LoadQuickInfo();
-    }
-
-    private void LoadQuickInfo()
-    {
-        QuickTasks.Clear();
-        if (SelectedGroup is null)
-        {
-            QuickHasNextLesson = false; QuickNextLessonLabel = "";
-            QuickHasNextExam = false; QuickNextExamLabel = "";
-            OnPropertyChanged(nameof(QuickHasTasks));
-            OnPropertyChanged(nameof(QuickHasAnything));
-            return;
-        }
-
-        var groupId = SelectedGroup.Id;
-        var today = DateOnly.FromDateTime(DateTime.Today);
-
-        var nextLesson = _lessons.GetByGroupAndRange(groupId, today, today.AddDays(90))
-            .Where(l => l.Status == LessonStatus.Planned)
-            .OrderBy(l => l.Date).ThenBy(l => l.LessonNumber ?? 0).FirstOrDefault();
-        QuickHasNextLesson = nextLesson is not null;
-        QuickNextLessonLabel = nextLesson is null ? ""
-            : string.IsNullOrWhiteSpace(nextLesson.Topic)
-                ? nextLesson.Date.ToString("dd.MM.yyyy")
-                : $"{nextLesson.Date:dd.MM.yyyy} — {nextLesson.Topic}";
-
-        var nextExam = _exams.GetByGroup(groupId).Where(e => e.Date >= today).MinBy(e => e.Date);
-        QuickHasNextExam = nextExam is not null;
-        QuickNextExamLabel = nextExam is null ? "" : $"{nextExam.Date:dd.MM.yyyy} — {nextExam.Title}";
-
-        foreach (var t in _tasks.GetByGroup(groupId).Where(t => t.Status != WorkTaskStatus.Done)
-                     .OrderBy(t => t.DueDate ?? DateOnly.MaxValue).Take(QuickTasksMaxCount))
-            QuickTasks.Add(new GroupTaskItem(t.Title, t.Kind == TaskKind.Reminder,
-                t.DueDate?.ToString("dd.MM.yyyy") ?? "", t.DueDate is { } d && d < today,
-                TaskPriorityDisplay.ColorHex(t.Priority), t.Priority == TaskPriority.High));
-        OnPropertyChanged(nameof(QuickHasTasks));
-        OnPropertyChanged(nameof(QuickHasAnything));
-    }
-
     public void LoadGroups()
     {
-        var selectedId = SelectedGroup?.Id;
         Groups.Clear();
         var all = _groups.GetBySchoolYear(SelectedSchoolYear, includeInactive: ShowArchived)
             .Where(g => g.IsActive != ShowArchived);
@@ -129,8 +59,18 @@ public partial class GroupListViewModel : ObservableObject
                           || (g.SubjectId is Guid id && subjectNames.GetValueOrDefault(id, "")
                               .Contains(SearchText, StringComparison.OrdinalIgnoreCase)));
         foreach (var g in filtered.OrderBy(g => g.Name))
-            Groups.Add(new GroupListItem(g, g.SubjectId is Guid id ? subjectNames.GetValueOrDefault(id, "") : ""));
+        {
-        SelectedGroup = Groups.FirstOrDefault(g => g.Id == selectedId);
+            var item = new GroupListItem(g,
+                g.SubjectId is Guid id ? subjectNames.GetValueOrDefault(id, "") : "")
+            {
+                OnOpen = OpenGroup,
+                OnEdit = EditGroup,
+                OnRollOver = RollOverGroup,
+                OnToggleArchive = ToggleArchive,
+                OnDelete = DeleteGroup,
+            };
+            Groups.Add(item);
+        }
         OnPropertyChanged(nameof(ListSummary));
         OnPropertyChanged(nameof(HasNoGroups));
         OnPropertyChanged(nameof(EmptyListMessage));
@@ -145,63 +85,57 @@ public partial class GroupListViewModel : ObservableObject
     }
     [RelayCommand] private void Refresh()   => LoadGroups();
 
-    [RelayCommand(CanExecute = nameof(CanEditSelectedGroup))]
+    [RelayCommand]
-    private async Task EditGroup()
+    private void OpenGroup(GroupListItem? group)
     {
-        if (SelectedGroup is null || OnEditGroup is null) return;
+        if (group is not null) OnNavigateToDetail?.Invoke(group.Id, 0);
-        var id = SelectedGroup.Id;
-        await OnEditGroup(id);
-        LoadGroups();
-        SelectedGroup = Groups.FirstOrDefault(g => g.Id == id);
     }
 
-    [RelayCommand(CanExecute = nameof(HasSelectedGroup))]
+    [RelayCommand]
-    private async Task RollOverGroup()
+    private async Task EditGroup(GroupListItem? group)
     {
-        if (SelectedGroup is null || OnRollOverGroup is null) return;
+        if (group?.IsActive != true || OnEditGroup is null) return;
-        var targetId = await OnRollOverGroup(SelectedGroup.Id);
+        var id = group.Id;
+        await OnEditGroup(id);
+        LoadGroups();
+    }
+
+    [RelayCommand]
+    private async Task RollOverGroup(GroupListItem? group)
+    {
+        if (group is null || OnRollOverGroup is null) return;
+        var targetId = await OnRollOverGroup(group.Id);
         if (targetId is null) return;
         var target = _groups.GetById(targetId.Value);
         if (target is null) return;
         if (!SchoolYears.Contains(target.SchoolYear)) SchoolYears.Insert(0, target.SchoolYear);
         SelectedSchoolYear = target.SchoolYear;
         LoadGroups();
-        SelectedGroup = Groups.FirstOrDefault(g => g.Id == target.Id);
+        OnNavigateToDetail?.Invoke(target.Id, 0);
     }
 
-    [RelayCommand(CanExecute = nameof(HasSelectedGroup))]
+    [RelayCommand]
-    private void ToggleArchive()
+    private void ToggleArchive(GroupListItem? selected)
     {
-        if (SelectedGroup is null) return;
+        if (selected is null) return;
-        var group = _groups.GetById(SelectedGroup.Id);
+        var group = _groups.GetById(selected.Id);
         if (group is null) return;
         group.IsActive = !group.IsActive;
         _groups.Save(group);
         LoadGroups();
     }
 
-    [RelayCommand(CanExecute = nameof(CanEditSelectedGroup))]
+    [RelayCommand]
-    private async Task DeleteGroup()
+    private async Task DeleteGroup(GroupListItem? group)
     {
-        if (SelectedGroup is null || OnConfirmDelete is null) return;
+        if (group?.IsActive != true || OnConfirmDelete is null) return;
-        var selected = SelectedGroup;
+        if (!await OnConfirmDelete(group)) return;
-        if (!await OnConfirmDelete(selected)) return;
+        _groups.Delete(group.Id);
-        _groups.Delete(selected.Id);
         LoadGroups();
     }
-
-    [RelayCommand(CanExecute = nameof(HasSelectedGroup))]
-    private void NavigateToSection(string? tabIndex)
-    {
-        if (SelectedGroup is null || !int.TryParse(tabIndex, out var tab)) return;
-        OnNavigateToDetail?.Invoke(SelectedGroup.Id, tab);
-    }
-
-    private bool HasSelectedGroup() => SelectedGroup is not null;
-    private bool CanEditSelectedGroup() => SelectedGroup?.IsActive == true;
 }
 
-public class GroupListItem
+public partial class GroupListItem : ObservableObject
 {
     public Guid Id { get; }
     public string Name { get; }
@@ -212,6 +146,13 @@ public class GroupListItem
     public string Subtitle { get; }
     public bool IsActive { get; }
     public string ArchiveActionLabel => IsActive ? "Archivieren" : "Wieder aktivieren";
+    public string OpenAutomationName => $"Lerngruppe {DisplayName} öffnen";
+    public string ManageAutomationName => $"Lerngruppe {DisplayName} verwalten";
+    public Action<GroupListItem>? OnOpen { get; init; }
+    public Func<GroupListItem, Task>? OnEdit { get; init; }
+    public Func<GroupListItem, Task>? OnRollOver { get; init; }
+    public Action<GroupListItem>? OnToggleArchive { get; init; }
+    public Func<GroupListItem, Task>? OnDelete { get; init; }
 
     public GroupListItem(LearningGroup g, string subjectName)
     {
@@ -224,6 +165,12 @@ public class GroupListItem
         DisplayName  = string.IsNullOrEmpty(subjectName) ? g.Name : $"{g.Name} · {subjectName}";
         Subtitle     = $"{TypeLabel} · Stufe {g.GradeLevel} · Noten {GradingLabel} · {g.SchoolYear}";
     }
+
+    [RelayCommand] private void Open() => OnOpen?.Invoke(this);
+    [RelayCommand] private Task Edit() => OnEdit?.Invoke(this) ?? Task.CompletedTask;
+    [RelayCommand] private Task RollOver() => OnRollOver?.Invoke(this) ?? Task.CompletedTask;
+    [RelayCommand] private void ToggleArchive() => OnToggleArchive?.Invoke(this);
+    [RelayCommand] private Task Delete() => OnDelete?.Invoke(this) ?? Task.CompletedTask;
 }
 
 // ── Gruppendetail ─────────────────────────────────────────────────────────────
@@ -878,6 +825,7 @@ public partial class AddGroupDialogViewModel : ObservableObject
     [ObservableProperty] private bool _isOwnClass;
     [ObservableProperty] private bool _isDifferentiated;
     [ObservableProperty] private bool _requiresLessonPlanning = true;
+    [ObservableProperty] private int? _webUntisLessonId;
     [ObservableProperty] private string _nameError = "";
     [ObservableProperty] private string _gradeLevelError = "";
 
@@ -917,6 +865,7 @@ public partial class AddGroupDialogViewModel : ObservableObject
         IsOwnClass = group.IsOwnClass;
         IsDifferentiated = group.IsDifferentiated;
         RequiresLessonPlanning = group.RequiresLessonPlanning;
+        WebUntisLessonId = group.WebUntisLessonId;
         OnPropertyChanged(nameof(DialogTitle));
         OnPropertyChanged(nameof(SaveButtonText));
     }
@@ -963,6 +912,7 @@ public partial class AddGroupDialogViewModel : ObservableObject
         Result.IsOwnClass    = IsOwnClass;
         Result.IsDifferentiated = IsDifferentiated;
         Result.RequiresLessonPlanning = RequiresLessonPlanning;
+        Result.WebUntisLessonId = WebUntisLessonId;
         _groups.Save(Result);
     }
 }

LehrerApp.Desktop/ViewModels/Groups/SeatingPlanViewModels.cs

@@ -236,6 +236,13 @@ public partial class SeatingPlanTabViewModel : ObservableObject
         NotifyCommands();
     }
 
+    /// Öffentlich statt intern (kein InternalsVisibleTo in dieser Codebasis, siehe
+    /// UntisSyncService-Kommentar): der Unterrichtsmodus bewertet über eine zweite, unabhängige
+    /// ParticipationTabViewModel-Instanz (Schnellbewertungs-Dialoge, siehe TeachingModeWindow) —
+    /// diese Instanz hier bekommt davon nichts automatisch mit und muss nach jedem Dialog explizit
+    /// neu aus dem Repository laden, damit die Sitzplatz-Badges nicht veraltet bleiben.
+    public void ReloadSeatBadgesFromRepository() => RefreshSeatLessonData();
+
     private void RefreshSeatLessonData()
     {
         if (SelectedSession is null)

LehrerApp.Desktop/ViewModels/Groups/TeachingModeViewModel.cs

@@ -1,3 +1,5 @@
+using CommunityToolkit.Mvvm.ComponentModel;
+using CommunityToolkit.Mvvm.Input;
 using LehrerApp.Core.Interfaces;
 using LehrerApp.Core.Models;
 
@@ -10,24 +12,104 @@ namespace LehrerApp.Desktop.ViewModels.Groups;
 /// der "Heute"-Tagesliste heraus gestartet.
 ///
 /// Bewusst keine eigene DI-Registrierung als Singleton/Transient: wie LessonViewerViewModel wird
-/// diese ViewModel direkt vom Code-Behind konstruiert, das dafür nötige SeatingPlanTabViewModel
+/// diese ViewModel direkt vom Code-Behind konstruiert, das dafür nötige SeatingPlanTabViewModel/
-/// aber weiterhin über DI aufgelöst (transient, siehe AppBootstrapper) und hier per Konstruktor
+/// ParticipationTabViewModel aber weiterhin über DI aufgelöst (transient, siehe AppBootstrapper)
-/// entgegengenommen statt selbst aus App.Services zu ziehen - ViewModels greifen in diesem Code
+/// und hier per Konstruktor entgegengenommen statt selbst aus App.Services zu ziehen -
-/// nicht selbst auf den Service-Container zu, das bleibt Aufgabe des Code-Behind.
+/// ViewModels greifen in diesem Code nicht selbst auf den Service-Container zu, das bleibt
+/// Aufgabe des Code-Behind.
 /// </summary>
 public class TeachingModeViewModel
 {
     public string GroupName { get; }
     public LessonViewerViewModel LessonInfo { get; }
     public SeatingPlanTabViewModel SeatingPlan { get; }
+    /// <summary>Nutzer-Feedback: die Schnellbewertungs-Dialoge für Mitarbeit/Anwesenheit-Hausaufgabe
+    /// gab es bislang nur über den Mitarbeit-Tab der Gruppe — im Unterrichtsmodus musste man dafür
+    /// erst wieder raus. Hier dieselbe <see cref="ParticipationTabViewModel"/> wie im Mitarbeit-Tab,
+    /// aber auf die zu dieser Stunde gehörende Sitzung vorselektiert (siehe Konstruktor), damit die
+    /// über <c>OnQuickInput</c>/<c>OnStatusQuickInput</c> geöffneten Dialoge (Wiring in
+    /// TeachingModeWindow.axaml.cs, gleiches Muster wie ParticipationTabView.axaml.cs) direkt auf
+    /// der richtigen Sitzung starten.</summary>
+    public ParticipationTabViewModel Participation { get; }
+    public TeachingModeHomeworkViewModel Homework { get; }
 
     public TeachingModeViewModel(Lesson lesson, LearningGroup group,
-        IAlternativeLessonPathRepository alternativePaths, SeatingPlanTabViewModel seatingPlan)
+        IAlternativeLessonPathRepository alternativePaths, ILessonRepository lessons,
+        SeatingPlanTabViewModel seatingPlan, ParticipationTabViewModel participation)
     {
         GroupName = group.Name;
         LessonInfo = new LessonViewerViewModel(lesson, alternativePaths);
+
         SeatingPlan = seatingPlan;
         SeatingPlan.Initialize(group.Id, !group.IsActive);
         SeatingPlan.SelectOrCreateSessionForLesson(lesson);
+
+        Participation = participation;
+        Participation.Initialize(group.Id, group.SchoolYear, !group.IsActive);
+        if (SeatingPlan.SelectedSession is { } linkedSession)
+            Participation.SelectedSession =
+                Participation.Sessions.FirstOrDefault(s => s.Id == linkedSession.Id);
+
+        // 4.5.4: dieselbe "letzte Stunde vor dieser"-Suche wie das Stundenplan-Badge
+        // "Hausaufgabe kontrollieren" (TimetableViewModel.HasUnhandledHomework) - 120 Tage
+        // Lookback deckt auch längere Ferienpausen ab, ohne unbegrenzt weit zurückzuscannen.
+        var previousLesson = lessons.GetByGroupAndRange(group.Id, lesson.Date.AddDays(-120), lesson.Date.AddDays(-1))
+            .OrderByDescending(l => l.Date).ThenByDescending(l => l.LessonNumber ?? 0)
+            .FirstOrDefault();
+        Homework = new TeachingModeHomeworkViewModel(lesson, previousLesson, lessons);
+    }
+}
+
+/// <summary>
+/// Nutzer-Feedback: im Unterrichtsmodus sollte man die Hausaufgabe aus der letzten Stunde als
+/// kontrolliert abhaken und die neue Hausaufgabe eintragen/ändern können, ohne dafür den vollen
+/// <see cref="LehrerApp.Desktop.Views.Groups.LessonDialog"/>-Editor zu öffnen (der zusätzlich Phasen/Reflexion usw. zeigt)
+/// - manchmal ergibt sich die Hausaufgabe erst während der Stunde. Bewusst eine eigene, kleine
+/// <see cref="ObservableObject"/> statt Felder direkt auf <see cref="TeachingModeViewModel"/>, da
+/// diese Klasse (wie <see cref="LessonViewerViewModel"/>) selbst keine Bindable-Basisklasse hat.
+/// </summary>
+public partial class TeachingModeHomeworkViewModel : ObservableObject
+{
+    private readonly ILessonRepository _lessons;
+    private readonly Lesson _lesson;
+    private readonly Lesson? _previousLesson;
+
+    public bool HasPreviousHomework =>
+        _previousLesson is not null && !string.IsNullOrWhiteSpace(_previousLesson.Homework);
+    public string PreviousHomeworkText => _previousLesson?.Homework ?? "";
+    public string PreviousLessonLabel => _previousLesson is null ? "" :
+        $"{_previousLesson.Date:dd.MM.yyyy}" + (string.IsNullOrWhiteSpace(_previousLesson.Topic)
+            ? "" : $" · {_previousLesson.Topic}");
+
+    [ObservableProperty] private bool _previousHomeworkChecked;
+    [ObservableProperty] private string _currentHomework;
+    [ObservableProperty] private string _saveStatus = "";
+
+    public TeachingModeHomeworkViewModel(Lesson lesson, Lesson? previousLesson, ILessonRepository lessons)
+    {
+        _lesson = lesson;
+        _previousLesson = previousLesson;
+        _lessons = lessons;
+        _previousHomeworkChecked = previousLesson?.HomeworkChecked ?? false;
+        _currentHomework = lesson.Homework ?? "";
+    }
+
+    /// Sofort beim Umschalten gespeichert (kein separater Speichern-Klick nötig) - dieselbe
+    /// Checkbox-Semantik wie im LessonDialog (4.5.4): "kontrolliert" und "nicht kontrollieren"
+    /// schließen sich aus.
+    partial void OnPreviousHomeworkCheckedChanged(bool value)
+    {
+        if (_previousLesson is null) return;
+        _previousLesson.HomeworkChecked = value;
+        if (value) _previousLesson.HomeworkCheckDismissed = false;
+        _lessons.Save(_previousLesson);
+    }
+
+    [RelayCommand]
+    private void SaveCurrentHomework()
+    {
+        _lesson.Homework = CurrentHomework;
+        _lessons.Save(_lesson);
+        SaveStatus = "Gespeichert.";
     }
 }

LehrerApp.Desktop/ViewModels/Groups/WebUntisClassSelectionViewModel.cs

@@ -0,0 +1,56 @@
+using System.Collections.ObjectModel;
+using CommunityToolkit.Mvvm.ComponentModel;
+using CommunityToolkit.Mvvm.Input;
+using LehrerApp.Desktop.Services;
+
+namespace LehrerApp.Desktop.ViewModels.Groups;
+
+public partial class WebUntisClassSelectionViewModel(WebUntisIntegrationService untis) : ObservableObject
+{
+    public ObservableCollection<UntisSchoolYearDto> SchoolYears { get; } = [];
+    public ObservableCollection<UntisClassDto> Classes { get; } = [];
+    [ObservableProperty] private UntisSchoolYearDto? _selectedSchoolYear;
+    [ObservableProperty] private UntisClassDto? _selectedClass;
+    [ObservableProperty] private string _status = "";
+    [ObservableProperty] private bool _busy;
+    public bool CanConfirm => SelectedClass is not null && !Busy;
+
+    partial void OnSelectedClassChanged(UntisClassDto? value) => OnPropertyChanged(nameof(CanConfirm));
+    partial void OnBusyChanged(bool value) => OnPropertyChanged(nameof(CanConfirm));
+
+    public async Task InitializeAsync()
+    {
+        Busy = true;
+        try
+        {
+            foreach (var year in (await untis.GetSchoolYearsAsync()).OrderByDescending(x => x.StartDate))
+                SchoolYears.Add(year);
+            SelectedSchoolYear = SchoolYears.FirstOrDefault(x => x.StartDate <= Today() && x.EndDate >= Today())
+                                 ?? SchoolYears.FirstOrDefault();
+            await LoadClasses();
+        }
+        catch (WebUntisIntegrationException ex) { Status = ex.Message; }
+        finally { Busy = false; }
+    }
+
+    [RelayCommand]
+    private async Task LoadClasses()
+    {
+        if (SelectedSchoolYear is null) return;
+        Busy = true; Classes.Clear(); SelectedClass = null;
+        try
+        {
+            foreach (var entry in (await untis.GetClassesAsync(SelectedSchoolYear.UntisId)).OrderBy(x => x.Name))
+                Classes.Add(entry);
+            Status = Classes.Count == 0 ? "Keine Klassen gefunden." : $"{Classes.Count} Klassen gefunden.";
+        }
+        catch (WebUntisIntegrationException ex) { Status = ex.Message; }
+        finally { Busy = false; }
+    }
+
+    private static int Today()
+    {
+        var date = DateOnly.FromDateTime(DateTime.Today);
+        return date.Year * 10000 + date.Month * 100 + date.Day;
+    }
+}

LehrerApp.Desktop/ViewModels/Groups/WebUntisLessonAbsenceComparisonViewModel.cs

@@ -0,0 +1,238 @@
+using System.Collections.ObjectModel;
+using CommunityToolkit.Mvvm.ComponentModel;
+using CommunityToolkit.Mvvm.Input;
+using LehrerApp.Core.Importing;
+using LehrerApp.Core.Interfaces;
+using LehrerApp.Core.Models;
+using LehrerApp.Desktop.Services;
+
+namespace LehrerApp.Desktop.ViewModels.Groups;
+
+/// <summary>Eine Zeile bleibt auch ohne automatische Zuordnung sichtbar (statt stillschweigend
+/// weggefiltert zu werden) - <see cref="AssignedStudent"/> kann manuell per Auswahlliste gesetzt
+/// werden, wenn weder `ENr` noch der Name eindeutig auf ein Kursmitglied passen.</summary>
+public partial class WebUntisLessonAbsenceRow : ObservableObject
+{
+    public required string UntisStudentName { get; init; }
+    public required DateOnly Date { get; init; }
+    public required string TimeLabel { get; init; }
+    public required string UntisStatus { get; init; }
+    public required AttendanceStatus TargetStatus { get; init; }
+    public required IReadOnlyList<Student> Candidates { get; init; }
+    internal Action<WebUntisLessonAbsenceRow>? OnAssignmentChanged { get; init; }
+    public string? Reason { get; init; }
+    public string DateLabel => Date.ToString("dd.MM.yyyy");
+    public bool CanApply => SessionId is not null;
+
+    [ObservableProperty] private Student? _assignedStudent;
+    [ObservableProperty] private string _localStatus = "ohne Zuordnung";
+    [ObservableProperty] private Guid? _sessionId;
+    [ObservableProperty] private bool _selected;
+
+    partial void OnAssignedStudentChanged(Student? value) => OnAssignmentChanged?.Invoke(this);
+}
+
+/// <summary>Fehlzeitenabgleich über den "Fehlzeiten pro Unterricht"-Bericht (<see cref="LearningGroup.WebUntisLessonId"/>).
+/// Der früher genutzte, pro Schüler abgerufene Fehlzeiten-Report (getTimetableWithAbsences) brauchte
+/// weitergehende WebUntis-Rechte als dieser Lerngruppen-Bericht und wurde deshalb entfernt.</summary>
+public partial class WebUntisLessonAbsenceComparisonViewModel : ObservableObject
+{
+    private readonly LearningGroup _group;
+    private readonly WebUntisIntegrationService _untis;
+    private readonly IStudentRepository _students;
+    private readonly IParticipationSessionRepository _sessions;
+    private readonly IParticipationRepository _participation;
+
+    private IReadOnlyList<Student> _loadedStudents = [];
+    private IReadOnlyDictionary<DateOnly, ParticipationSession> _loadedSessions =
+        new Dictionary<DateOnly, ParticipationSession>();
+
+    public ObservableCollection<WebUntisLessonAbsenceRow> Rows { get; } = [];
+    [ObservableProperty] private DateTimeOffset _startDate = DateTimeOffset.Now.AddMonths(-2);
+    [ObservableProperty] private DateTimeOffset _endDate = DateTimeOffset.Now;
+    [ObservableProperty] private string _status = "Zeitraum wählen und Fehlzeiten laden.";
+    [ObservableProperty] private bool _busy;
+    [ObservableProperty] private bool _markUnknownAsPresent;
+
+    public WebUntisLessonAbsenceComparisonViewModel(LearningGroup group, WebUntisIntegrationService untis,
+        IStudentRepository students, IParticipationSessionRepository sessions,
+        IParticipationRepository participation)
+    {
+        _group = group; _untis = untis; _students = students; _sessions = sessions;
+        _participation = participation;
+    }
+
+    [RelayCommand]
+    private async Task Load()
+    {
+        var lessonId = _group.WebUntisLessonId;
+        if (lessonId is null)
+        {
+            Status = "Für diese Lerngruppe ist noch keine WebUntis-Unterrichtsnummer hinterlegt " +
+                     "(Gruppe bearbeiten).";
+            return;
+        }
+
+        var start = DateOnly.FromDateTime(StartDate.LocalDateTime);
+        var end = DateOnly.FromDateTime(EndDate.LocalDateTime);
+        if (end < start) { Status = "Das Enddatum darf nicht vor dem Startdatum liegen."; return; }
+        Busy = true; Rows.Clear();
+        try
+        {
+            var courseStudents = _students.GetByGroup(_group.Id);
+            var localSessions = _sessions.GetByGroup(_group.Id)
+                .Where(x => x.Date >= start && x.Date <= end).GroupBy(x => x.Date)
+                .ToDictionary(x => x.Key, x => x.First());
+            _loadedStudents = courseStudents;
+            _loadedSessions = localSessions;
+            // Erste Wahl: WebUntis-Kennung (ENr). Nicht jeder Schüler hat eine (z.B. manuell statt
+            // per WebUntis-Import angelegt) - Fallback über den Namen, aber nur wenn er innerhalb
+            // der Kursmitglieder eindeutig ist, sonst lieber unzugeordnet lassen als raten.
+            var byKey = courseStudents.Select(student => (Student: student, Key: StudentKey(student)))
+                .Where(x => x.Key is not null).ToDictionary(x => x.Key!.Value, x => x.Student);
+            var byName = courseStudents
+                .SelectMany(student => new[]
+                {
+                    NameKey($"{student.LastName} {student.FirstName}"),
+                    NameKey($"{student.FirstName} {student.LastName}"),
+                }.Select(key => (Key: key, Student: student)))
+                .GroupBy(x => x.Key)
+                .Where(group => group.Select(x => x.Student).Distinct().Count() == 1)
+                .ToDictionary(group => group.Key, group => group.First().Student);
+
+            var absences = await _untis.GetLessonAbsencesAsync(lessonId.Value, start, end);
+            var ordered = absences
+                .Select(absence => (Absence: absence, Date: TryDate(absence.Date, out var date) ? date : (DateOnly?)null))
+                .Where(x => x.Date is not null)
+                .OrderBy(x => x.Date).ThenBy(x => x.Absence.StudentName);
+
+            void ResolveLocalMatch(WebUntisLessonAbsenceRow row)
+            {
+                if (row.AssignedStudent is not { } student)
+                {
+                    row.SessionId = null; row.LocalStatus = "ohne Zuordnung"; row.Selected = false;
+                    return;
+                }
+                localSessions.TryGetValue(row.Date, out var session);
+                var entry = session is null ? null : _participation.GetBySessionAndStudent(session.Id, student.Id);
+                row.SessionId = session?.Id;
+                row.LocalStatus = session is null ? "keine lokale Stunde" : AttendanceDisplay.Label(entry?.Attendance);
+                row.Selected = session is not null && entry?.Attendance != row.TargetStatus;
+            }
+
+            foreach (var (absence, date) in ordered)
+            {
+                var match = absence.ExternKey is { } key && byKey.TryGetValue(key, out var byKeyStudent)
+                    ? byKeyStudent
+                    : byName.GetValueOrDefault(NameKey(absence.StudentName));
+                var row = new WebUntisLessonAbsenceRow
+                {
+                    UntisStudentName = absence.StudentName, Date = date!.Value,
+                    TimeLabel = TimeLabel(absence.StartTime, absence.EndTime),
+                    UntisStatus = DisplayUntisStatus(absence),
+                    TargetStatus = MapStatus(absence), Reason = absence.Reason,
+                    Candidates = courseStudents, OnAssignmentChanged = ResolveLocalMatch,
+                };
+                Rows.Add(row);
+                row.AssignedStudent = match; // löst OnAssignedStudentChanged aus und setzt SessionId/LocalStatus/Selected
+            }
+
+            var unresolved = Rows.Count(x => x.AssignedStudent is null);
+            Status = $"{absences.Count} Fehlzeiten von WebUntis erhalten, {Rows.Count - unresolved} automatisch zugeordnet" +
+                     (unresolved > 0 ? $", {unresolved} bitte manuell zuordnen" : "") +
+                     $". {Rows.Count(x => x.CanApply)} sind einer lokalen Kursstunde zuordenbar.";
+        }
+        catch (WebUntisIntegrationException ex) { Status = ex.Message; }
+        finally { Busy = false; }
+    }
+
+    [RelayCommand]
+    private void Apply()
+    {
+        var selected = Rows.Where(x => x.Selected && x.SessionId is not null && x.AssignedStudent is not null).ToList();
+        foreach (var row in selected)
+        {
+            var studentId = row.AssignedStudent!.Id;
+            var entry = _participation.GetBySessionAndStudent(row.SessionId!.Value, studentId)
+                        ?? new ParticipationEntry { SessionId = row.SessionId.Value, StudentId = studentId };
+            entry.Attendance = row.TargetStatus;
+            entry.UpdatedAt = DateTime.UtcNow;
+            _participation.Save(entry);
+        }
+
+        var presentCount = MarkUnknownAsPresent ? FillUnknownAsPresent() : 0;
+        Status = $"{selected.Count} Anwesenheitsstatus übernommen." +
+                 (MarkUnknownAsPresent ? $" {presentCount} unbekannte Status auf anwesend gesetzt." : "");
+        foreach (var row in selected) row.Selected = false;
+    }
+
+    // "Identifiziert" heißt hier: WebUntis hat für diesen Schüler an diesem Tag überhaupt eine Zeile
+    // gemeldet - unabhängig davon, ob die Zeile markiert/übernommen wurde. Nur wer für den geladenen
+    // Zeitraum weder von WebUntis gemeldet noch lokal schon kontrolliert wurde, gilt als "unbekannt"
+    // und wird auf anwesend gesetzt; bereits erfasste Einträge (auch ohne Anwesenheitsstatus, z.B. nur
+    // mit Notiz) werden nicht überschrieben, wenn ihr Anwesenheitsstatus schon gesetzt ist.
+    private int FillUnknownAsPresent()
+    {
+        var identified = Rows.Where(x => x.AssignedStudent is not null)
+            .Select(x => (x.Date, StudentId: x.AssignedStudent!.Id))
+            .ToHashSet();
+        var filled = 0;
+        foreach (var session in _loadedSessions.Values)
+        foreach (var student in _loadedStudents)
+        {
+            if (identified.Contains((session.Date, student.Id))) continue;
+            var entry = _participation.GetBySessionAndStudent(session.Id, student.Id);
+            if (entry?.Attendance is not null) continue;
+            entry ??= new ParticipationEntry { SessionId = session.Id, StudentId = student.Id };
+            entry.Attendance = AttendanceStatus.Present;
+            entry.UpdatedAt = DateTime.UtcNow;
+            _participation.Save(entry);
+            filled++;
+        }
+        return filled;
+    }
+
+    private static int? StudentKey(Student student)
+    {
+        student.ExternalIds ??= [];
+        return student.ExternalIds.TryGetValue(StudentImportFormats.MasterDataCsv.Value, out var value)
+               && int.TryParse(value, out var key) ? key : null;
+    }
+
+    // Groß-/Kleinschreibung, Leerraum und - da die tatsächliche WebUntis-Reihenfolge nicht
+    // dokumentiert und schulabhängig unterschiedlich beobachtet wurde - beide Namensreihenfolgen
+    // werden beim Aufbau von `byName` registriert; hier wird nur normalisiert.
+    private static string NameKey(string value) => value.Trim().ToLowerInvariant();
+
+    private const int FullLessonMinutes = 45;
+
+    // Der Bericht liefert keinen Entschuldigungstext, nur Minutenwerte, ein Bearbeitet-Datum und die
+    // (laut Schule) über Klammerung der ENr codierte Entscheidung des Klassenlehrers - ENr in
+    // Klammern bedeutet unentschuldigt, ohne Klammern abgeschlossen/entschuldigt. Reihenfolge ist
+    // wichtig: "nach Hause entlassen" zählt immer als vorzeitige Entlassung, unabhängig von der
+    // Dauer; darunter zählt jede Fehlzeit unter einer vollen Stunde (45 Min.) immer als Verspätung
+    // oder sonstiger Teilverlust, nie als komplette Abwesenheit - der Text "Verspätung" allein ist
+    // laut Schule nicht zuverlässig genug, deshalb primär über die Minutenschwelle erkannt.
+    private static AttendanceStatus MapStatus(UntisLessonAbsenceDto absence)
+    {
+        if (IsEarlyRelease(absence)) return AttendanceStatus.LeftDuringClass;
+        if (absence.AbsentMinutes < FullLessonMinutes) return AttendanceStatus.Late;
+        if (string.IsNullOrWhiteSpace(absence.HandledOn)) return AttendanceStatus.ExcusePending;
+        if (absence.ExternKey is null) return AttendanceStatus.ExcusePending;
+        return absence.ExternKeyInParentheses ? AttendanceStatus.Unexcused : AttendanceStatus.Excused;
+    }
+
+    private static bool IsEarlyRelease(UntisLessonAbsenceDto absence) =>
+        absence.Reason?.Contains("entlassen", StringComparison.OrdinalIgnoreCase) == true;
+
+    // Nutzt dieselben deutschen Bezeichnungen wie die reguläre Mitarbeitserfassung
+    // (AttendanceDisplay.Label), statt eigene Statustexte zu erfinden.
+    private static string DisplayUntisStatus(UntisLessonAbsenceDto absence) =>
+        string.Join(" · ", new[] { AttendanceDisplay.Label(MapStatus(absence)), absence.Reason }
+            .Where(x => !string.IsNullOrWhiteSpace(x)));
+
+    private static bool TryDate(int value, out DateOnly date) => DateOnly.TryParseExact(value.ToString(), "yyyyMMdd", out date);
+    private static string TimeLabel(int? start, int? end) =>
+        start is null || end is null ? "" : $"{Time(start.Value)}–{Time(end.Value)}";
+    private static string Time(int value) => $"{value / 100:00}:{value % 100:00}";
+}

LehrerApp.Desktop/ViewModels/MainWindowViewModel.cs

@@ -3,6 +3,8 @@ using CommunityToolkit.Mvvm.ComponentModel;
 using CommunityToolkit.Mvvm.Input;
 using LehrerApp.Core.Services;
 using LehrerApp.Desktop.Services;
+using LehrerApp.Desktop.ViewModels.ClassTeacher;
+using LehrerApp.Desktop.ViewModels.Exams;
 using LehrerApp.Desktop.ViewModels.Groups;
 using LehrerApp.Desktop.ViewModels.Planning;
 using LehrerApp.Desktop.ViewModels.Settings;
@@ -20,10 +22,12 @@ public partial class MainWindowViewModel : ObservableObject
     [ObservableProperty] private ObservableObject? _currentPage;
     [ObservableProperty] private NavItem _activeNavItem = NavItem.Dashboard;
     [ObservableProperty] private string _currentSchoolYear = "";
+    [ObservableProperty] private bool _isCommandPaletteOpen;
 
     public SyncStatusViewModel SyncStatus { get; }
     public ObservableCollection<ToastItem> Toasts { get; }
     public AppLockViewModel AppLock { get; }
+    public GlobalSearchViewModel CommandPalette { get; }
 
     public bool IsDashboardActive => ActiveNavItem == NavItem.Dashboard;
     public bool IsGroupsActive    => ActiveNavItem == NavItem.Groups;
@@ -31,22 +35,37 @@ public partial class MainWindowViewModel : ObservableObject
     public bool IsExamsActive     => ActiveNavItem == NavItem.Exams;
     public bool IsPlannerActive   => ActiveNavItem == NavItem.Planner;
     public bool IsWorkloadActive  => ActiveNavItem == NavItem.Workload;
+    public bool IsClassTeacherActive => ActiveNavItem == NavItem.ClassTeacher;
     public bool IsSettingsActive  => ActiveNavItem == NavItem.Settings;
 
     public MainWindowViewModel(IServiceProvider services,
         DashboardViewModel dashboard, SchoolYearService sy,
-        SyncStatusViewModel syncStatus, NotificationService notifications, AppLockViewModel appLock)
+        SyncStatusViewModel syncStatus, NotificationService notifications, AppLockViewModel appLock,
+        GlobalSearchViewModel commandPalette)
     {
         _services         = services;
         SyncStatus        = syncStatus;
         Toasts            = notifications.Toasts;
         AppLock           = appLock;
+        CommandPalette    = commandPalette;
+        CommandPalette.OnClose = CloseCommandPalette;
         CurrentSchoolYear = sy.CurrentSchoolYear();
         CurrentPage       = dashboard;
         AppLock.ApplyConfig();
         SyncStatus.DataChanged += OnSyncDataChanged;
     }
 
+    [RelayCommand]
+    private void OpenCommandPalette()
+    {
+        if (AppLock.IsLocked) return;
+        CommandPalette.Reset();
+        IsCommandPaletteOpen = true;
+    }
+
+    [RelayCommand]
+    private void CloseCommandPalette() => IsCommandPaletteOpen = false;
+
     // EventApplier schreibt bei eingehenden Sync-Ereignissen absichtlich direkt auf die rohe
     // LiteDB-Collection, an jedem ViewModel vorbei (Ping-Pong-Vermeidung, siehe EventApplier-
     // Klassenkommentar) - ohne diesen Hook blieb die gerade sichtbare Seite bis zum nächsten
@@ -71,6 +90,8 @@ public partial class MainWindowViewModel : ObservableObject
             case TimetableViewModel vm: vm.Load(); break;
             case WorkloadViewModel vm:
                 vm.Tasks.Load(); vm.TimeTracking.Load(); vm.Evaluation.Load(); break;
+            case ClassTeacherOverviewViewModel vm: vm.LoadCommand.Execute(null); break;
+            case ExamsOverviewViewModel vm: vm.LoadCommand.Execute(null); break;
             case GroupDetailViewModel { Group: { } group } vm: vm.LoadGroup(group.Id); break;
             // Inline-Bearbeitung (IsEditing) nicht überschreiben - anders als die Gruppenansicht
             // laufen Namens-/Geschlechtsänderungen hier nicht über einen Dialog.
@@ -87,6 +108,7 @@ public partial class MainWindowViewModel : ObservableObject
         OnPropertyChanged(nameof(IsExamsActive));
         OnPropertyChanged(nameof(IsPlannerActive));
         OnPropertyChanged(nameof(IsWorkloadActive));
+        OnPropertyChanged(nameof(IsClassTeacherActive));
         OnPropertyChanged(nameof(IsSettingsActive));
     }
 
@@ -99,9 +121,10 @@ public partial class MainWindowViewModel : ObservableObject
             NavItem.Dashboard => GetDashboard(),
             NavItem.Groups    => _services.GetRequiredService<GroupListViewModel>(),
             NavItem.Students  => GetStudents(),
-            NavItem.Exams     => new PlaceholderViewModel { Title = "Klausuren", Icon = "📝" },
+            NavItem.Exams     => GetExams(),
             NavItem.Planner   => GetTimetable(),
             NavItem.Workload  => GetWorkload(),
+            NavItem.ClassTeacher => GetClassTeacherOverview(),
             NavItem.Settings  => _services.GetRequiredService<SettingsViewModel>(),
             _                 => CurrentPage,
         };
@@ -141,6 +164,22 @@ public partial class MainWindowViewModel : ObservableObject
         return workload;
     }
 
+    private ExamsOverviewViewModel GetExams()
+    {
+        var exams = _services.GetRequiredService<ExamsOverviewViewModel>();
+        exams.LoadCommand.Execute(null);
+        return exams;
+    }
+
+    private ClassTeacherOverviewViewModel GetClassTeacherOverview()
+    {
+        var vm = _services.GetRequiredService<ClassTeacherOverviewViewModel>();
+        vm.OnNavigateToSettings = () => { NavigateToSettings(SettingsTab.WebUntis); return Task.CompletedTask; };
+        vm.OnNavigateToWorkload = () => { NavigateToWorkload(); return Task.CompletedTask; };
+        vm.LoadCommand.Execute(null);
+        return vm;
+    }
+
     public void NavigateToGroupDetail(Guid groupId, int initialTab = 0)
     {
         ActiveNavItem     = NavItem.Groups;
@@ -175,7 +214,7 @@ public partial class MainWindowViewModel : ObservableObject
     public void NavigateToWorkload() => NavigateTo(NavItem.Workload);
 }
 
-public enum NavItem { Dashboard, Groups, Students, Exams, Planner, Workload, Settings }
+public enum NavItem { Dashboard, Groups, Students, Exams, Planner, Workload, ClassTeacher, Settings }
 
 public partial class PlaceholderViewModel : ObservableObject
 {

LehrerApp.Desktop/ViewModels/Planning/TimetableViewModel.cs

@@ -65,6 +65,7 @@ public partial class TimetableViewModel : ObservableObject
     private readonly ISubstitutionEntryRepository _substitutions;
     private readonly IUntisSlotMappingRepository _untisMappings;
     private readonly WebUntisSettingsService _untisSettings;
+    private readonly PeriodScheduleService _periodSchedule;
     private readonly SchoolWeatherService? _schoolWeather;
     private readonly SemaphoreSlim _weatherGate = new(1, 1);
     private WeatherSnapshot? _weatherSnapshot;
@@ -103,23 +104,30 @@ public partial class TimetableViewModel : ObservableObject
     public Func<TimetableCellItem, Task>? OnEditSlot { get; set; }
     public Action<Guid>? OnNavigateToGroup { get; set; }
     public Func<Task>? OnAddSubstitution { get; set; }
+    public Func<Task>? OnImportWebUntisTimetable { get; set; }
     public Action<SettingsTab>? OnNavigateToSettings { get; set; }
     public Func<Lesson, Task>? OnOpenLessonViewer { get; set; }
     public Func<Lesson, Task>? OnOpenTeachingMode { get; set; }
 
+    /// Öffentlich statt intern (kein InternalsVisibleTo in dieser Codebasis) - erlaubt Tests, die
+    /// "heute"-abhängiges Verhalten (Wochenraster-Badges, Unterrichtszeit-Erkennung) prüfen, ohne
+    /// vom tatsächlichen Wochentag/der Uhrzeit im Testlauf abzuhängen.
+    public Func<DateTime> Clock { get; set; } = () => DateTime.Now;
+
     public TimetableViewModel(ITimetableSlotRepository slots, IGroupRepository groups,
         ISubjectRepository subjects, ILessonRepository lessons, IExamRepository exams,
         ISchoolHolidayRepository schoolHolidays, SchoolCalendarSettingsService calendarSettings,
         PublicHolidayService publicHolidays, SchoolYearService schoolYear,
         ISupervisionDutyRepository supervisionDuties, ISubstitutionEntryRepository substitutions,
         IUntisSlotMappingRepository untisMappings, WebUntisSettingsService untisSettings,
-        SchoolWeatherService? schoolWeather = null)
+        PeriodScheduleService periodSchedule, SchoolWeatherService? schoolWeather = null)
     {
         _slots = slots; _groups = groups; _subjects = subjects; _lessons = lessons; _exams = exams;
         _schoolHolidays = schoolHolidays; _calendarSettings = calendarSettings;
         _publicHolidays = publicHolidays; _schoolYear = schoolYear;
         _supervisionDuties = supervisionDuties; _substitutions = substitutions;
         _untisMappings = untisMappings; _untisSettings = untisSettings;
+        _periodSchedule = periodSchedule;
         _schoolWeather = schoolWeather;
         Load();
     }
@@ -143,9 +151,17 @@ public partial class TimetableViewModel : ObservableObject
         Load();
     }
 
+    [RelayCommand]
+    private async Task ImportWebUntisTimetable()
+    {
+        if (OnImportWebUntisTimetable is null) return;
+        await OnImportWebUntisTimetable();
+        Load();
+    }
+
     public void Load()
     {
-        var today = DateOnly.FromDateTime(DateTime.Today);
+        var today = DateOnly.FromDateTime(Clock());
         TodayLabel = today.ToString("dddd, dd.MM.yyyy", System.Globalization.CultureInfo.GetCultureInfo("de-DE"));
 
         var publicHolidayDates = new HashSet<DateOnly>();
@@ -359,14 +375,42 @@ public partial class TimetableViewModel : ObservableObject
         await OnOpenTeachingMode(lesson);
     }
 
+    /// Nutzer-Feedback (zweite Runde): der Direktklick auf eine Wochenraster-Kachel soll
+    /// "einheitlicher" springen. Existiert eine Lesson UND ist gerade (heute, mit Toleranz vor/
+    /// nach der Stunde) Unterrichtszeit, geht es direkt in den Unterrichtsmodus — sonst wie
+    /// bisher in den (schreibgeschützten) Planungsviewer bzw., ohne Lesson, zur Einheitenplanung
+    /// der Gruppe. Das Popup-Menü (siehe TimetableView.axaml, MenuFlyout je Kachel) bietet
+    /// daneben immer alle vier Ziele explizit an, unabhängig von dieser Automatik.
     [RelayCommand]
     private async Task OpenWeekCell(WeekCellItem? item)
     {
         if (item is null || item.GroupId == Guid.Empty) return;
-        if (item.Lesson is { } lesson && OnOpenLessonViewer is not null) await OnOpenLessonViewer(lesson);
+        if (item.Lesson is { } lesson)
+        {
+            if (IsAroundTeachingTime(lesson.Date, item.PeriodNumber) && OnOpenTeachingMode is not null)
+                await OnOpenTeachingMode(lesson);
+            else if (OnOpenLessonViewer is not null) await OnOpenLessonViewer(lesson);
+        }
         else OnNavigateToGroup?.Invoke(item.GroupId);
     }
 
+    /// Bewusst mit Toleranz vor/nach der eingetragenen Stundenzeit (siehe
+    /// <see cref="PeriodScheduleService"/>, "Stundenraster" in den Einstellungen) statt exakt an
+    /// Start-/Endzeit gebunden — man klickt auch kurz vor Stundenbeginn oder in einer kurzen
+    /// Verzögerung danach noch typischerweise in Unterrichtsabsicht. Ohne konfiguriertes
+    /// Stundenraster oder an einem anderen Tag als heute bleibt es beim Planungsviewer.
+    /// Nimmt bewusst das Datum der Lesson selbst statt WeekCellItem.Date entgegen — Date ist dort
+    /// nur bei Kopfzeilen (WeekdayHeader) gesetzt, nicht bei regulären Stunden-Kacheln (ForSlot).
+    private static readonly TimeSpan TeachingTimeTolerance = TimeSpan.FromMinutes(10);
+    private bool IsAroundTeachingTime(DateOnly lessonDate, int periodNumber)
+    {
+        var nowSnapshot = Clock();
+        if (lessonDate != DateOnly.FromDateTime(nowSnapshot)) return false;
+        if (_periodSchedule.GetTimes(periodNumber) is not { } times) return false;
+        var now = TimeOnly.FromDateTime(nowSnapshot);
+        return now >= times.Start.Add(-TeachingTimeTolerance) && now <= times.End.Add(TeachingTimeTolerance);
+    }
+
     [RelayCommand]
     private void OpenSettings() => OnNavigateToSettings?.Invoke(SettingsTab.Holidays);
 
@@ -775,9 +819,11 @@ public partial class WeekCellItem : ObservableObject
     public bool HasSupervision => SupervisionLocation.Length > 0;
     public bool HasRoom => !string.IsNullOrWhiteSpace(Room);
     public bool HasTopic => !string.IsNullOrWhiteSpace(Topic);
+    public bool HasGroupId => GroupId != Guid.Empty;
     /// Nur bei einer regulären, zugewiesenen Zelle mit bereits existierender Lesson gesetzt —
     /// Grundlage für den Direktsprung in den Verlaufsplan-Viewer (4.5.2).
     public Lesson? Lesson { get; private init; }
+    public bool HasLesson => Lesson is not null;
     public string OpenButtonLabel => Lesson is not null ? "Verlaufsplan ansehen" : "Zur Lerngruppe";
     [ObservableProperty] private string _weatherSymbol = "";
     [ObservableProperty] private string _weatherTooltip = "";
@@ -891,6 +937,9 @@ public class UpcomingExamItem(DateOnly date, string groupName, string title)
     public string Title { get; } = title;
 }
 
+public enum TimetableLessonDestination { TeachingMode, Viewer, SeatingPlan, Planning }
+public sealed record TimetableDestinationOption(TimetableLessonDestination Kind, string Label);
+
 public class TodayLessonItem
 {
     public Guid GroupId { get; private init; }

LehrerApp.Desktop/ViewModels/Planning/WebUntisTimetableImportViewModel.cs

@@ -0,0 +1,159 @@
+using System.Collections.ObjectModel;
+using CommunityToolkit.Mvvm.ComponentModel;
+using CommunityToolkit.Mvvm.Input;
+using LehrerApp.Core.Interfaces;
+using LehrerApp.Core.Models;
+using LehrerApp.Desktop.Services;
+
+namespace LehrerApp.Desktop.ViewModels.Planning;
+
+public sealed record WebUntisGroupOption(Guid Id, string DisplayName);
+
+public partial class WebUntisTimetableRow : ObservableObject
+{
+    public required DayOfWeek Weekday { get; init; }
+    public required int PeriodNumber { get; init; }
+    public required string TimeLabel { get; init; }
+    public required string UntisLabel { get; init; }
+    public required string SuggestedGroupName { get; init; }
+    public string? SubjectName { get; init; }
+    public string? Room { get; init; }
+    public ObservableCollection<WebUntisGroupOption> GroupOptions { get; } = [];
+    [ObservableProperty] private WebUntisGroupOption? _selectedGroup;
+    public string WeekdayLabel => Weekday switch
+    {
+        DayOfWeek.Monday => "Mo", DayOfWeek.Tuesday => "Di", DayOfWeek.Wednesday => "Mi",
+        DayOfWeek.Thursday => "Do", DayOfWeek.Friday => "Fr", _ => Weekday.ToString()[..2],
+    };
+}
+
+public partial class WebUntisTimetableImportViewModel : ObservableObject
+{
+    private readonly WebUntisIntegrationService _untis;
+    private readonly WebUntisSettingsService _settings;
+    private readonly ITimetableSlotRepository _slots;
+    private readonly IGroupRepository _groups;
+
+    public ObservableCollection<UntisTeacherDto> Teachers { get; } = [];
+    public ObservableCollection<WebUntisTimetableRow> Rows { get; } = [];
+    [ObservableProperty] private UntisTeacherDto? _selectedTeacher;
+    [ObservableProperty] private DateTimeOffset _weekDate = DateTimeOffset.Now;
+    [ObservableProperty] private string _status = "Lehrkraft auswählen und Untis-Woche laden.";
+    [ObservableProperty] private bool _busy;
+    public bool Saved { get; private set; }
+    public Func<WebUntisTimetableRow, Task<LearningGroup?>>? OnCreateGroup { get; set; }
+
+    public WebUntisTimetableImportViewModel(WebUntisIntegrationService untis, WebUntisSettingsService settings,
+        ITimetableSlotRepository slots, IGroupRepository groups)
+    {
+        _untis = untis; _settings = settings; _slots = slots; _groups = groups;
+    }
+
+    public async Task InitializeAsync()
+    {
+        Busy = true;
+        try
+        {
+            foreach (var teacher in (await _untis.GetTeachersAsync()).Where(x => x.Active).OrderBy(x => x.DisplayName))
+                Teachers.Add(teacher);
+            SelectedTeacher = Teachers.FirstOrDefault(x => x.UntisId == _settings.TeacherUntisId)
+                              ?? Teachers.FirstOrDefault();
+            Status = Teachers.Count == 0 ? "WebUntis hat keine Lehrkräfte geliefert." : "Bereit zum Laden.";
+        }
+        catch (WebUntisIntegrationException ex) { Status = ex.Message; }
+        finally { Busy = false; }
+    }
+
+    [RelayCommand]
+    private async Task Load()
+    {
+        if (SelectedTeacher is null) { Status = "Bitte eine Lehrkraft auswählen."; return; }
+        Busy = true; Rows.Clear();
+        try
+        {
+            var selected = DateOnly.FromDateTime(WeekDate.LocalDateTime);
+            var monday = selected.AddDays(-(((int)selected.DayOfWeek + 6) % 7));
+            var periods = await _untis.GetTimetableAsync(SelectedTeacher.UntisId, monday, monday.AddDays(6));
+            var grid = await _untis.GetTimeGridAsync();
+            var groupOptions = BuildGroupOptions();
+            var localSlots = _slots.GetAll().ToDictionary(x => (x.Weekday, x.PeriodNumber));
+
+            foreach (var period in periods.Where(x => string.IsNullOrWhiteSpace(x.Code) || x.Code != "cancelled")
+                         .GroupBy(x => (x.Date, x.StartTime, x.EndTime, x.StudentGroup,
+                             Class: string.Join("/", x.Classes.Select(c => c.Name)),
+                             Subject: string.Join("/", x.Subjects.Select(s => s.Name)),
+                             Room: string.Join("/", x.Rooms.Select(r => r.Name))))
+                         .Select(x => x.First()).OrderBy(x => x.Date).ThenBy(x => x.StartTime))
+            {
+                if (!TryDate(period.Date, out var date) || date.DayOfWeek is DayOfWeek.Saturday or DayOfWeek.Sunday)
+                    continue;
+                var dayGrid = grid.FirstOrDefault(x => x.Day == UntisDay(date.DayOfWeek));
+                var number = dayGrid?.TimeUnits.ToList().FindIndex(x => x.StartTime == period.StartTime) + 1 ?? 0;
+                if (number <= 0) continue;
+                var className = period.Classes.FirstOrDefault()?.Name ?? "";
+                var subject = period.Subjects.FirstOrDefault()?.Name;
+                var suggested = !string.IsNullOrWhiteSpace(period.StudentGroup) ? period.StudentGroup! : className;
+                var row = new WebUntisTimetableRow
+                {
+                    Weekday = date.DayOfWeek, PeriodNumber = number,
+                    TimeLabel = $"{Time(period.StartTime)}–{Time(period.EndTime)}",
+                    UntisLabel = string.Join(" · ", new[] { subject, suggested, period.Rooms.FirstOrDefault()?.Name }
+                        .Where(x => !string.IsNullOrWhiteSpace(x))),
+                    SuggestedGroupName = suggested, SubjectName = subject,
+                    Room = period.Rooms.FirstOrDefault()?.Name,
+                };
+                foreach (var option in groupOptions) row.GroupOptions.Add(option);
+                if (localSlots.TryGetValue((row.Weekday, row.PeriodNumber), out var existing))
+                    row.SelectedGroup = groupOptions.FirstOrDefault(x => x.Id == existing.GroupId);
+                row.SelectedGroup ??= BestMatch(groupOptions, suggested, className, subject);
+                Rows.Add(row);
+            }
+            _settings.SetTeacherUntisId(SelectedTeacher.UntisId);
+            Status = Rows.Count == 0 ? "In dieser Woche wurde kein Unterricht gefunden."
+                : $"{Rows.Count} regelmäßige Termine gefunden. Zuordnung prüfen und übernehmen.";
+        }
+        catch (WebUntisIntegrationException ex) { Status = ex.Message; }
+        finally { Busy = false; }
+    }
+
+    [RelayCommand]
+    private async Task CreateGroup(WebUntisTimetableRow row)
+    {
+        if (OnCreateGroup is null) return;
+        var group = await OnCreateGroup(row);
+        if (group is null) return;
+        var option = new WebUntisGroupOption(group.Id, group.Name);
+        foreach (var item in Rows.Where(x => x.SuggestedGroupName == row.SuggestedGroupName))
+        {
+            item.GroupOptions.Add(option);
+            item.SelectedGroup = option;
+        }
+    }
+
+    [RelayCommand]
+    private void Save()
+    {
+        var selected = Rows.Where(x => x.SelectedGroup is not null).ToList();
+        foreach (var row in selected)
+        {
+            var existing = _slots.GetAll().FirstOrDefault(x => x.Weekday == row.Weekday && x.PeriodNumber == row.PeriodNumber);
+            var slot = existing ?? new TimetableSlot { Weekday = row.Weekday, PeriodNumber = row.PeriodNumber };
+            slot.GroupId = row.SelectedGroup!.Id;
+            slot.Room = string.IsNullOrWhiteSpace(row.Room) ? null : row.Room;
+            _slots.Save(slot);
+        }
+        Saved = true;
+        Status = $"{selected.Count} Stundenplan-Einträge übernommen.";
+    }
+
+    private List<WebUntisGroupOption> BuildGroupOptions() => _groups.GetAll().OrderBy(x => x.Name)
+        .Select(x => new WebUntisGroupOption(x.Id, x.Name)).ToList();
+
+    private static WebUntisGroupOption? BestMatch(IEnumerable<WebUntisGroupOption> options, params string?[] terms) =>
+        options.FirstOrDefault(x => terms.Any(term => !string.IsNullOrWhiteSpace(term) &&
+            (x.DisplayName.Equals(term, StringComparison.OrdinalIgnoreCase) ||
+             x.DisplayName.Contains(term, StringComparison.OrdinalIgnoreCase))));
+    private static int UntisDay(DayOfWeek day) => day == DayOfWeek.Sunday ? 7 : (int)day;
+    private static bool TryDate(int value, out DateOnly date) => DateOnly.TryParseExact(value.ToString(), "yyyyMMdd", out date);
+    private static string Time(int value) => $"{value / 100:00}:{value % 100:00}";
+}

LehrerApp.Desktop/ViewModels/Settings/SettingsViewModel.cs

@@ -210,7 +210,21 @@ public partial class SettingsViewModel : ObservableObject
     [ObservableProperty] private string _untisUrlError = "";
     [ObservableProperty] private string _untisStatusDisplay = "";
     [ObservableProperty] private bool   _untisFetchBusy;
+    [ObservableProperty] private bool   _untisApiIsConfigured;
+    [ObservableProperty] private string _untisSchool = "";
+    [ObservableProperty] private string _untisHost = "";
+    [ObservableProperty] private string _untisUsername = "";
+    [ObservableProperty] private string _untisPassword = "";
+    [ObservableProperty] private string _untisApiStatus = "";
+    [ObservableProperty] private bool   _untisApiBusy;
+    [ObservableProperty] private string? _untisHomeroomClassName;
+    public string UntisHomeroomClassDisplay => UntisHomeroomClassName is { Length: > 0 } name
+        ? $"Ausgewählt: {name}"
+        : "Keine Klasse ausgewählt.";
+    partial void OnUntisHomeroomClassNameChanged(string? value) => OnPropertyChanged(nameof(UntisHomeroomClassDisplay));
     public Func<Task>? OnReviewUntisMapping { get; set; }
+    /// Vom Code-Behind gesetzt: öffnet den WebUntis-Klassenauswahldialog, liefert null bei Abbruch.
+    public Func<Task<(int UntisId, string Name)?>>? OnPickHomeroomClass { get; set; }
 
     // ── Schulweiter Jahresplan (ClassyPlan-iCal) ─────────────────────────────
 
@@ -299,6 +313,7 @@ public partial class SettingsViewModel : ObservableObject
     private readonly AiSettingsService _aiSettings;
     private readonly AiPlanningService _aiPlanning;
     private readonly WebUntisSettingsService _untisSettings;
+    private readonly WebUntisIntegrationService? _untisIntegration;
     private readonly UntisSyncService? _untisSync;
     private readonly AnnualPlanSettingsService _annualPlanSettings;
     private readonly AnnualPlanSyncService? _annualPlanSync;
@@ -330,7 +345,7 @@ public partial class SettingsViewModel : ObservableObject
         AppearanceSettingsService appearance, TrashViewModel trashTab,
         SnapshotService? snapshotService = null, SyncEngine? syncEngine = null,
         UntisSyncService? untisSync = null, AnnualPlanSyncService? annualPlanSync = null,
-        SchoolWeatherService? schoolWeather = null)
+        SchoolWeatherService? schoolWeather = null, WebUntisIntegrationService? untisIntegration = null)
     {
         _logger = logger;
         _syncKeyRecovery = syncKeyRecovery;
@@ -360,6 +375,7 @@ public partial class SettingsViewModel : ObservableObject
         _aiSettings = aiSettings;
         _aiPlanning = aiPlanning;
         _untisSettings = untisSettings;
+        _untisIntegration = untisIntegration;
         _untisSync = untisSync;
         _annualPlanSettings = annualPlanSettings;
         _annualPlanSync = annualPlanSync;
@@ -542,6 +558,61 @@ public partial class SettingsViewModel : ObservableObject
         UntisStatusDisplay = _untisSettings.LastSyncAt is { } at
             ? $"Letzter Abgleich: {at.ToLocalTime():dd.MM.yyyy HH:mm} — {_untisSettings.LastSyncStatus}"
             : "Noch kein Abgleich durchgeführt.";
+        UntisApiIsConfigured = _untisSettings.ApiIsConfigured;
+        if (_untisSettings.GetApiCredentials() is { } credentials)
+        {
+            UntisSchool = credentials.School;
+            UntisHost = credentials.Host;
+            UntisUsername = credentials.Username;
+            UntisApiStatus = $"API-Zugang für {credentials.Username} ist lokal verschlüsselt gespeichert.";
+        }
+        UntisHomeroomClassName = _untisSettings.HomeroomClassName;
+    }
+
+    [RelayCommand]
+    private async Task UntisSaveApi()
+    {
+        UntisApiStatus = "";
+        if (_untisIntegration is null)
+        {
+            UntisApiStatus = "Die WebUntis-Integration ist nicht verfügbar.";
+            return;
+        }
+        if (string.IsNullOrWhiteSpace(UntisSchool) || string.IsNullOrWhiteSpace(UntisUsername) ||
+            string.IsNullOrWhiteSpace(UntisPassword))
+        {
+            UntisApiStatus = "Schule, Benutzername und Passwort sind erforderlich.";
+            return;
+        }
+        UntisApiBusy = true;
+        try
+        {
+            var credentials = new WebUntisCredentials(UntisSchool.Trim(), UntisHost.Trim(),
+                UntisUsername.Trim(), UntisPassword);
+            await _untisIntegration.ConnectAsync(credentials);
+            _untisSettings.SetApiCredentials(credentials);
+            UntisPassword = "";
+            UntisApiIsConfigured = true;
+            UntisApiStatus = "Anmeldung erfolgreich. Die WebUntis-Session bleibt bei Nutzung bis zu 10 Minuten offen.";
+        }
+        catch (WebUntisIntegrationException ex) { UntisApiStatus = ex.Message; }
+        finally { UntisApiBusy = false; }
+    }
+
+    [RelayCommand]
+    private async Task UntisRemoveApi()
+    {
+        UntisApiBusy = true;
+        try { if (_untisIntegration is not null) await _untisIntegration.DisconnectAsync(); }
+        catch (WebUntisIntegrationException) { /* lokale Zugangsdaten trotzdem sicher entfernen */ }
+        finally
+        {
+            _untisSettings.ClearApiCredentials();
+            UntisPassword = "";
+            UntisApiIsConfigured = false;
+            UntisApiStatus = "WebUntis-API-Zugang entfernt.";
+            UntisApiBusy = false;
+        }
     }
 
     [RelayCommand]
@@ -584,6 +655,23 @@ public partial class SettingsViewModel : ObservableObject
         if (OnReviewUntisMapping is not null) await OnReviewUntisMapping();
     }
 
+    [RelayCommand]
+    private async Task UntisPickHomeroomClass()
+    {
+        if (OnPickHomeroomClass is null) return;
+        var result = await OnPickHomeroomClass();
+        if (result is null) return;
+        _untisSettings.SetHomeroomClass(result.Value.UntisId, result.Value.Name);
+        LoadUntisSettings();
+    }
+
+    [RelayCommand]
+    private void UntisClearHomeroomClass()
+    {
+        _untisSettings.SetHomeroomClass(null, null);
+        LoadUntisSettings();
+    }
+
     // ── Schulweiter Jahresplan: Laden / Speichern / Entfernen / Jetzt abrufen ─
 
     private void LoadAnnualPlanSettings()

LehrerApp.Desktop/ViewModels/Students/DocumentationViewModels.cs

@@ -107,6 +107,7 @@ public partial class DocumentationDialogViewModel : ObservableObject
     [ObservableProperty] private string _title = "";
     [ObservableProperty] private string _content = "";
     [ObservableProperty] private bool _isConfidential;
+    [ObservableProperty] private bool _excludeFromWebUntisSync;
 
     [ObservableProperty] private string _newParticipant = "";
     public ObservableCollection<string> Participants { get; } = [];
@@ -176,6 +177,7 @@ public partial class DocumentationDialogViewModel : ObservableObject
         Title = editing.Title;
         Content = editing.Content;
         IsConfidential = editing.IsConfidential;
+        ExcludeFromWebUntisSync = editing.ExcludeFromWebUntisSync;
         foreach (var p in editing.Participants) Participants.Add(p);
         if (editing.AbsenceData is { } a)
         {
@@ -343,6 +345,7 @@ public partial class DocumentationDialogViewModel : ObservableObject
         // Schnellentwurf ab. Stunden- und Lesson-Bezug bleiben am bestehenden Objekt erhalten.
         Result.IsDraft = false;
         Result.IsConfidential = IsConfidential;
+        Result.ExcludeFromWebUntisSync = ExcludeFromWebUntisSync;
         Result.Participants = type == DocumentationType.Conversation ? Participants.ToList() : [];
         Result.AbsenceData = type == DocumentationType.Absence
             ? new AbsenceData

LehrerApp.Desktop/ViewModels/Students/WebUntisDocumentationComparisonViewModel.cs

@@ -0,0 +1,192 @@
+using System.Collections.ObjectModel;
+using CommunityToolkit.Mvvm.ComponentModel;
+using CommunityToolkit.Mvvm.Input;
+using LehrerApp.Core.Interfaces;
+using LehrerApp.Core.Models;
+using LehrerApp.Core.Services;
+using LehrerApp.Desktop.Services;
+
+namespace LehrerApp.Desktop.ViewModels.Students;
+
+/// <summary>Eine Zeile bleibt auch ohne automatische Zuordnung sichtbar - <see cref="AssignedStudent"/>
+/// kann manuell per Auswahlliste gesetzt werden, wenn der Name nicht eindeutig auf ein/e Schüler*in
+/// passt (siehe WebUntisLessonAbsenceComparisonViewModel für dasselbe Muster).</summary>
+public partial class WebUntisDocumentationRow : ObservableObject
+{
+    public required string ClassName { get; init; }
+    public required DateOnly Date { get; init; }
+    public required string UntisStudentName { get; init; }
+    public string? Subject { get; init; }
+    public string? CategoryName { get; init; }
+    public string? CategoryGroup { get; init; }
+    public string? Text { get; init; }
+    public required IReadOnlyList<Student> Candidates { get; init; }
+    public string DateLabel => Date.ToString("dd.MM.yyyy");
+    public bool CanApply => AssignedStudent is not null;
+
+    [ObservableProperty] private Student? _assignedStudent;
+    /// <summary>Titel/Text eines lokalen Eintrags, der am selben Tag für diese/n Schüler*in schon
+    /// existiert - nur nach Datum+Schüler*in erkannt, nicht nach Wortlaut (der unterscheidet sich oft
+    /// von der WebUntis-Kategorie). Deshalb Anzeige zum Vergleichen statt automatischem Ausblenden.</summary>
+    [ObservableProperty] private string? _existingLocalEntry;
+    [ObservableProperty] private bool _selected;
+}
+
+/// <summary>Lokaler Dokumentationseintrag im geladenen Zeitraum ohne passenden WebUntis-Eintrag - kann
+/// nicht automatisch nach WebUntis geschrieben werden (bewusst keine schreibenden Aufrufe gegen die
+/// undokumentierte API), deshalb nur als Kopiervorlage für die manuelle Nacherfassung dort.</summary>
+public sealed record LocalOnlyDocumentationRow(
+    string StudentName, DateOnly Date, string? GroupName, string Title, string Content)
+{
+    public string DateLabel => Date.ToString("dd.MM.yyyy");
+    public string ClipboardText =>
+        $"{DateLabel} – {StudentName}" + (GroupName is null ? "" : $" ({GroupName})") +
+        $"\n{Title}\n{Content}";
+}
+
+/// <summary>Abgleich der WebUntis-Klassenbucheinträge (eigene, siehe
+/// <see cref="WebUntisIntegrationService.GetOwnClassRegisterEventsAsync"/>) gegen die lokale
+/// <see cref="Documentation"/> - Dashboard-weit statt pro Lerngruppe, weil der WebUntis-"-alle-"-
+/// Bericht ebenfalls klassenübergreifend ist (siehe TODO.md, Nachtrag zu 4.3).</summary>
+public partial class WebUntisDocumentationComparisonViewModel : ObservableObject
+{
+    private readonly WebUntisIntegrationService _untis;
+    private readonly IStudentRepository _students;
+    private readonly IGroupRepository _groups;
+    private readonly IDocumentationRepository _documentation;
+    private readonly SchoolYearService _schoolYears;
+
+    public ObservableCollection<WebUntisDocumentationRow> Rows { get; } = [];
+    public ObservableCollection<LocalOnlyDocumentationRow> LocalOnlyRows { get; } = [];
+    [ObservableProperty] private DateTimeOffset _startDate = DateTimeOffset.Now.AddDays(-7);
+    [ObservableProperty] private DateTimeOffset _endDate = DateTimeOffset.Now;
+    [ObservableProperty] private string _status = "Zeitraum wählen und Klassenbucheinträge laden.";
+    [ObservableProperty] private bool _busy;
+
+    public WebUntisDocumentationComparisonViewModel(WebUntisIntegrationService untis,
+        IStudentRepository students, IGroupRepository groups, IDocumentationRepository documentation,
+        SchoolYearService schoolYears)
+    {
+        _untis = untis; _students = students; _groups = groups; _documentation = documentation;
+        _schoolYears = schoolYears;
+    }
+
+    [RelayCommand]
+    private async Task Load()
+    {
+        var start = DateOnly.FromDateTime(StartDate.LocalDateTime);
+        var end = DateOnly.FromDateTime(EndDate.LocalDateTime);
+        if (end < start) { Status = "Das Enddatum darf nicht vor dem Startdatum liegen."; return; }
+        Busy = true; Rows.Clear(); LocalOnlyRows.Clear();
+        try
+        {
+            var ownStudents = _students.GetAll();
+            var globalIndex = BuildNameIndex(ownStudents);
+            // Zusätzlich pro Klasse (aktuelles Schuljahr) indiziert: löst den Fall "gleicher Name in
+            // verschiedenen Klassen" auf, den ein rein globaler Namensabgleich nicht unterscheiden könnte.
+            var currentSchoolYear = _schoolYears.CurrentSchoolYear();
+            var classIndexes = _groups.GetAll()
+                .Where(g => g.Type == GroupType.Class && g.SchoolYear == currentSchoolYear)
+                .GroupBy(g => g.Name, StringComparer.OrdinalIgnoreCase)
+                .ToDictionary(
+                    g => g.Key,
+                    g => BuildNameIndex(g.SelectMany(x => _students.GetByGroup(x.Id)).Distinct().ToList()),
+                    StringComparer.OrdinalIgnoreCase);
+
+            var entries = await _untis.GetOwnClassRegisterEventsAsync(start, end);
+            var localDocs = _documentation.GetAll().Where(d => d.Date >= start && d.Date <= end).ToList();
+
+            var ordered = entries
+                .Select(e => (Entry: e, Date: TryDate(e.Date, out var d) ? d : (DateOnly?)null))
+                .Where(x => x.Date is not null)
+                .OrderBy(x => x.Date).ThenBy(x => x.Entry.StudentName);
+
+            // Nur nach Schüler*in+Datum erkannt, nicht nach Wortlaut: ein lokaler Eintrag von vor dieser
+            // Funktion (oder frei formuliert) hat selten denselben Titel wie die WebUntis-Kategorie.
+            List<Documentation> LocalDocsFor(Guid studentId, DateOnly date) =>
+                localDocs.Where(d => d.StudentId == studentId && d.Date == date).ToList();
+
+            foreach (var (entry, date) in ordered)
+            {
+                var nameKey = NameKey(entry.StudentName);
+                var match = (classIndexes.TryGetValue(entry.ClassName, out var classIndex)
+                        ? classIndex.GetValueOrDefault(nameKey)
+                        : null)
+                    ?? globalIndex.GetValueOrDefault(nameKey);
+                var existing = match is null ? [] : LocalDocsFor(match.Id, date!.Value);
+
+                Rows.Add(new WebUntisDocumentationRow
+                {
+                    ClassName = entry.ClassName, Date = date!.Value, UntisStudentName = entry.StudentName,
+                    Subject = entry.Subject, CategoryName = entry.CategoryName, CategoryGroup = entry.CategoryGroup,
+                    Text = entry.Text, Candidates = ownStudents, AssignedStudent = match,
+                    ExistingLocalEntry = existing.Count == 0 ? null
+                        : string.Join(" | ", existing.Select(d => $"{d.Title}: {d.Content}")),
+                    Selected = match is not null && existing.Count == 0,
+                });
+            }
+
+            foreach (var doc in localDocs)
+            {
+                if (doc.ExcludeFromWebUntisSync) continue;
+                var coveredByReport = Rows.Any(r => r.AssignedStudent?.Id == doc.StudentId && r.Date == doc.Date);
+                if (coveredByReport) continue;
+                var student = ownStudents.FirstOrDefault(s => s.Id == doc.StudentId);
+                if (student is null) continue;
+                LocalOnlyRows.Add(new LocalOnlyDocumentationRow(student.FullName, doc.Date,
+                    doc.GroupId is { } groupId ? _groups.GetById(groupId)?.Name : null, doc.Title, doc.Content));
+            }
+
+            var unresolved = Rows.Count(x => x.AssignedStudent is null);
+            var possibleDuplicates = Rows.Count(x => x.ExistingLocalEntry is not null);
+            Status = $"{Rows.Count} WebUntis-Einträge erhalten, {possibleDuplicates} mit lokalem Eintrag am " +
+                     "selben Tag (bitte vergleichen)" +
+                     (unresolved > 0 ? $", {unresolved} bitte manuell zuordnen" : "") +
+                     $". {LocalOnlyRows.Count} lokale Einträge ohne WebUntis-Gegenstück.";
+        }
+        catch (WebUntisIntegrationException ex) { Status = ex.Message; }
+        finally { Busy = false; }
+    }
+
+    [RelayCommand]
+    private void Apply()
+    {
+        var selected = Rows.Where(x => x.Selected && x.CanApply).ToList();
+        foreach (var row in selected)
+        {
+            _documentation.Save(new Documentation
+            {
+                StudentId = row.AssignedStudent!.Id,
+                Date = row.Date,
+                Type = DocumentationType.Incident,
+                Title = row.CategoryName ?? "WebUntis-Klassenbucheintrag",
+                Content = row.Text ?? "",
+                Tags = row.CategoryGroup is { Length: > 0 } group ? [group] : [],
+            });
+        }
+        foreach (var row in selected)
+        {
+            row.ExistingLocalEntry = $"{row.CategoryName}: {row.Text}";
+            row.Selected = false;
+        }
+        Status = $"{selected.Count} Einträge aus WebUntis übernommen.";
+    }
+
+    private static string NameKey(string value) => value.Trim().ToLowerInvariant();
+
+    // Wie beim Fehlzeiten-Abgleich: WebUntis liefert Namen nicht einheitlich in einer Reihenfolge,
+    // deshalb werden beide Reihenfolgen registriert, aber nur falls innerhalb der Kandidaten eindeutig.
+    private static Dictionary<string, Student> BuildNameIndex(IReadOnlyList<Student> candidates) =>
+        candidates
+            .SelectMany(student => new[]
+            {
+                NameKey($"{student.LastName} {student.FirstName}"),
+                NameKey($"{student.FirstName} {student.LastName}"),
+            }.Select(key => (Key: key, Student: student)))
+            .GroupBy(x => x.Key)
+            .Where(group => group.Select(x => x.Student).Distinct().Count() == 1)
+            .ToDictionary(group => group.Key, group => group.First().Student);
+
+    private static bool TryDate(int value, out DateOnly date) =>
+        DateOnly.TryParseExact(value.ToString(), "yyyyMMdd", out date);
+}

LehrerApp.Desktop/Views/ClassTeacher/ClassTeacherAbsencesView.axaml

@@ -0,0 +1,101 @@
+<UserControl xmlns="https://github.com/avaloniaui"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:vm="clr-namespace:LehrerApp.Desktop.ViewModels.ClassTeacher"
+             x:Class="LehrerApp.Desktop.Views.ClassTeacher.ClassTeacherAbsencesView"
+             x:DataType="vm:ClassTeacherDetailsViewModel">
+
+  <UserControl.Styles>
+    <!-- Siehe Styles/SemanticBrushes.axaml: Farben per DynamicResource, damit der Theme-Wechsel
+         sie live austauscht; die Statusfarbe je Zeile kommt als Style-Klasse aus dem ViewModel. -->
+    <Style Selector="Border.filterCard">
+      <Setter Property="Background" Value="{DynamicResource AppCardBackgroundBrush}"/>
+      <Setter Property="BorderBrush" Value="{DynamicResource AppCardBorderBrush}"/>
+      <Setter Property="BorderThickness" Value="1"/>
+      <Setter Property="CornerRadius" Value="8"/>
+      <Setter Property="Padding" Value="10"/>
+    </Style>
+    <Style Selector="TextBlock.status">
+      <Setter Property="Foreground" Value="{DynamicResource AppStatusOkBrush}"/>
+    </Style>
+    <Style Selector="TextBlock.status.info">
+      <Setter Property="Foreground" Value="{DynamicResource AppStatusInfoBrush}"/>
+    </Style>
+    <Style Selector="TextBlock.status.warning">
+      <Setter Property="Foreground" Value="{DynamicResource AppStatusWarningBrush}"/>
+    </Style>
+    <Style Selector="TextBlock.status.danger">
+      <Setter Property="Foreground" Value="{DynamicResource AppStatusDangerBrush}"/>
+    </Style>
+  </UserControl.Styles>
+
+  <Grid RowDefinitions="Auto,Auto,*,Auto" Margin="16" RowSpacing="10">
+    <Grid Grid.Row="0" ColumnDefinitions="*,Auto">
+      <StackPanel>
+        <TextBlock Text="Fehlzeiten" FontSize="22" FontWeight="SemiBold"/>
+        <TextBlock Text="Pro Schüler*in und Tag über alle Fächer zusammengefasst" FontSize="12" Opacity="0.55"/>
+      </StackPanel>
+      <Button Grid.Column="1" Content="↻  Aus WebUntis aktualisieren" Command="{Binding RefreshCommand}"
+              IsEnabled="{Binding !Busy}" Background="Transparent" Foreground="{DynamicResource AppAccentTextBrush}" VerticalAlignment="Center"/>
+    </Grid>
+
+    <Border Grid.Row="1" Classes="filterCard">
+      <Grid RowDefinitions="Auto,Auto" RowSpacing="8">
+        <Grid Grid.Row="0" ColumnDefinitions="155,Auto,*,Auto,*" ColumnSpacing="8">
+          <ComboBox Grid.Column="0" SelectedIndex="{Binding QuickRangeIndex, Mode=TwoWay}">
+            <ComboBoxItem Content="Heute"/><ComboBoxItem Content="Letzte 7 Tage"/><ComboBoxItem Content="Letzte 30 Tage"/>
+          </ComboBox>
+          <TextBlock Grid.Column="1" Text="von" VerticalAlignment="Center" Opacity="0.6"/>
+          <DatePicker Grid.Column="2" SelectedDate="{Binding StartDate}" HorizontalAlignment="Stretch"/>
+          <TextBlock Grid.Column="3" Text="bis" VerticalAlignment="Center" Opacity="0.6"/>
+          <DatePicker Grid.Column="4" SelectedDate="{Binding EndDate}" HorizontalAlignment="Stretch"/>
+        </Grid>
+        <Grid Grid.Row="1" ColumnDefinitions="*,Auto,Auto" ColumnSpacing="8">
+          <TextBox Grid.Column="0" Text="{Binding StudentFilter, Mode=TwoWay}" PlaceholderText="Schüler*in filtern…"/>
+          <Button Grid.Column="1" Content="Anzeigen" Command="{Binding ApplyFilterCommand}" IsEnabled="{Binding !Busy}"/>
+          <Button Grid.Column="2" Content="Filter löschen" Command="{Binding ClearStudentFilterCommand}"
+                  IsVisible="{Binding StudentFilter, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"/>
+        </Grid>
+      </Grid>
+    </Border>
+
+    <Grid Grid.Row="2">
+      <DataGrid ItemsSource="{Binding AbsenceEntries}" AutoGenerateColumns="False" IsReadOnly="True"
+                GridLinesVisibility="Horizontal" BorderBrush="{DynamicResource AppCardBorderBrush}" BorderThickness="1"
+                CanUserResizeColumns="True" CanUserSortColumns="True" RowHeight="48">
+        <DataGrid.Columns>
+          <DataGridTextColumn Header="Datum" Binding="{Binding DateLabel}" Width="105"/>
+          <DataGridTextColumn Header="Schüler*in" Binding="{Binding StudentDisplayName}" Width="1.3*"/>
+          <DataGridTemplateColumn Header="Art" Width="1.15*">
+            <DataGridTemplateColumn.CellTemplate>
+              <DataTemplate x:DataType="vm:ClassAbsenceDaySummaryRow">
+                <TextBlock Text="{Binding KindLabel}" Classes="status"
+                           Classes.warning="{Binding IsWarningStatus}"
+                           Classes.danger="{Binding IsDangerStatus}" VerticalAlignment="Center"/>
+              </DataTemplate>
+            </DataGridTemplateColumn.CellTemplate>
+          </DataGridTemplateColumn>
+          <DataGridTemplateColumn Header="Status" Width="1*">
+            <DataGridTemplateColumn.CellTemplate>
+              <DataTemplate x:DataType="vm:ClassAbsenceDaySummaryRow">
+                <Border Background="{DynamicResource AppChipBackgroundBrush}" CornerRadius="5"
+                        Padding="7,3" HorizontalAlignment="Left">
+                  <TextBlock Text="{Binding FriendlyStatusLabel}" Classes="status"
+                             Classes.warning="{Binding IsWarningStatus}"
+                             Classes.danger="{Binding IsDangerStatus}" FontSize="11"/>
+                </Border>
+              </DataTemplate>
+            </DataGridTemplateColumn.CellTemplate>
+          </DataGridTemplateColumn>
+          <DataGridTextColumn Header="Fächer" Binding="{Binding SubjectsLabel}" Width="1.2*"/>
+          <DataGridTextColumn Header="Stunden" Binding="{Binding PeriodsLabel}" Width="0.75*"/>
+          <DataGridTextColumn Header="Grund / Notiz" Binding="{Binding DetailLabel}" Width="2*"/>
+        </DataGrid.Columns>
+      </DataGrid>
+      <StackPanel IsVisible="{Binding !HasAbsenceEntries}" HorizontalAlignment="Center" VerticalAlignment="Center" Spacing="5">
+        <TextBlock Text="Keine Fehlzeiten im gewählten Zeitraum" FontWeight="SemiBold"/>
+        <TextBlock Text="Passe Zeitraum oder Schülerfilter an." FontSize="12" Opacity="0.55"/>
+      </StackPanel>
+    </Grid>
+    <TextBlock Grid.Row="3" Text="{Binding Status}" FontSize="11" Opacity="0.6"/>
+  </Grid>
+</UserControl>

LehrerApp.Desktop/Views/ClassTeacher/ClassTeacherAbsencesView.axaml.cs

@@ -0,0 +1,8 @@
+using Avalonia.Controls;
+
+namespace LehrerApp.Desktop.Views.ClassTeacher;
+
+public partial class ClassTeacherAbsencesView : UserControl
+{
+    public ClassTeacherAbsencesView() => InitializeComponent();
+}

LehrerApp.Desktop/Views/ClassTeacher/ClassTeacherOverviewView.axaml

@@ -0,0 +1,482 @@
+<UserControl xmlns="https://github.com/avaloniaui"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:vm="clr-namespace:LehrerApp.Desktop.ViewModels.ClassTeacher"
+             xmlns:views="clr-namespace:LehrerApp.Desktop.Views.ClassTeacher"
+             xmlns:conv="clr-namespace:LehrerApp.Desktop.Converters"
+             x:Class="LehrerApp.Desktop.Views.ClassTeacher.ClassTeacherOverviewView"
+             x:DataType="vm:ClassTeacherOverviewViewModel">
+
+  <!-- Flächen- und Statusfarben kommen aus Styles/SemanticBrushes.axaml und werden bewusst per
+       DynamicResource geholt, damit der Theme-Wechsel (hell/dunkel) sie live austauscht. Die
+       Statusfarbe einer Zeile setzt deshalb ein Style-Selektor über Klassen und nicht ein
+       Hex-String aus dem ViewModel — ein lokal gesetztes Attribut würde den Selektor überstimmen. -->
+  <UserControl.Styles>
+    <Style Selector="Border.metric">
+      <Setter Property="Background" Value="{DynamicResource AppCardBackgroundBrush}"/>
+      <Setter Property="BorderBrush" Value="{DynamicResource AppCardBorderBrush}"/>
+      <Setter Property="BorderThickness" Value="1"/>
+      <Setter Property="CornerRadius" Value="8"/>
+      <Setter Property="Padding" Value="14,12"/>
+      <Setter Property="Margin" Value="0,0,10,0"/>
+    </Style>
+    <Style Selector="Button.filter">
+      <Setter Property="Background" Value="Transparent"/>
+      <Setter Property="BorderBrush" Value="{DynamicResource AppFilterBorderBrush}"/>
+      <Setter Property="BorderThickness" Value="1"/>
+      <Setter Property="CornerRadius" Value="6"/>
+      <Setter Property="Padding" Value="16,6"/>
+      <Setter Property="FontSize" Value="12"/>
+    </Style>
+    <Style Selector="Button.filter.active">
+      <Setter Property="Background" Value="{DynamicResource AppFilterActiveBackgroundBrush}"/>
+      <Setter Property="BorderBrush" Value="{DynamicResource AppFilterActiveBorderBrush}"/>
+      <Setter Property="Foreground" Value="{DynamicResource AppFilterActiveForegroundBrush}"/>
+    </Style>
+    <Style Selector="Button.rosterRow">
+      <Setter Property="HorizontalAlignment" Value="Stretch"/>
+      <Setter Property="HorizontalContentAlignment" Value="Stretch"/>
+      <Setter Property="Background" Value="{DynamicResource AppListRowBackgroundBrush}"/>
+      <Setter Property="BorderBrush" Value="{DynamicResource AppListRowBorderBrush}"/>
+      <Setter Property="BorderThickness" Value="1,0,1,1"/>
+      <Setter Property="Padding" Value="0"/>
+      <Setter Property="MinHeight" Value="48"/>
+    </Style>
+    <Style Selector="Button.rosterRow:pointerover /template/ ContentPresenter">
+      <Setter Property="Background" Value="{DynamicResource AppListRowHoverBrush}"/>
+    </Style>
+    <Style Selector="Button.rosterRowAction">
+      <Setter Property="Width" Value="30"/>
+      <Setter Property="Height" Value="48"/>
+      <Setter Property="Background" Value="{DynamicResource AppListRowBackgroundBrush}"/>
+      <Setter Property="BorderBrush" Value="{DynamicResource AppListRowBorderBrush}"/>
+      <Setter Property="BorderThickness" Value="0,0,1,1"/>
+      <Setter Property="Foreground" Value="{DynamicResource AppAccentTextBrush}"/>
+      <Setter Property="FontSize" Value="16"/>
+      <Setter Property="Padding" Value="0"/>
+      <Setter Property="HorizontalContentAlignment" Value="Center"/>
+      <Setter Property="VerticalContentAlignment" Value="Center"/>
+    </Style>
+    <Style Selector="Button.rosterRowAction:pointerover /template/ ContentPresenter">
+      <Setter Property="Background" Value="{DynamicResource AppListRowHoverBrush}"/>
+    </Style>
+    <Style Selector="Border.sidePanel">
+      <Setter Property="Background" Value="{DynamicResource AppCardBackgroundBrush}"/>
+      <Setter Property="BorderBrush" Value="{DynamicResource AppCardBorderBrush}"/>
+      <Setter Property="BorderThickness" Value="1"/>
+      <Setter Property="CornerRadius" Value="8"/>
+      <Setter Property="Padding" Value="14"/>
+      <Setter Property="Margin" Value="0,0,0,10"/>
+    </Style>
+    <Style Selector="TextBlock.sectionLabel">
+      <Setter Property="FontSize" Value="13"/>
+      <Setter Property="FontWeight" Value="SemiBold"/>
+      <Setter Property="Margin" Value="4,10,0,6"/>
+    </Style>
+
+    <!-- Statusstufe: Basis ist "unauffällig", die Klassen aus dem ViewModel schalten hoch. -->
+    <Style Selector="TextBlock.status">
+      <Setter Property="Foreground" Value="{DynamicResource AppStatusOkBrush}"/>
+    </Style>
+    <Style Selector="TextBlock.status.info">
+      <Setter Property="Foreground" Value="{DynamicResource AppStatusInfoBrush}"/>
+    </Style>
+    <Style Selector="TextBlock.status.warning">
+      <Setter Property="Foreground" Value="{DynamicResource AppStatusWarningBrush}"/>
+    </Style>
+    <Style Selector="TextBlock.status.danger">
+      <Setter Property="Foreground" Value="{DynamicResource AppStatusDangerBrush}"/>
+    </Style>
+    <Style Selector="Border.statusFill">
+      <Setter Property="Background" Value="{DynamicResource AppStatusOkBrush}"/>
+    </Style>
+    <Style Selector="Border.statusFill.info">
+      <Setter Property="Background" Value="{DynamicResource AppStatusInfoBrush}"/>
+    </Style>
+    <Style Selector="Border.statusFill.warning">
+      <Setter Property="Background" Value="{DynamicResource AppStatusWarningBrush}"/>
+    </Style>
+    <Style Selector="Border.statusFill.danger">
+      <Setter Property="Background" Value="{DynamicResource AppStatusDangerBrush}"/>
+    </Style>
+  </UserControl.Styles>
+
+  <UserControl.Resources>
+    <!-- Eine Vorlage für beide Roster-Listen (auffällig / übrige): Sie waren Zeichen für Zeichen
+         identisch und mussten bisher doppelt gepflegt werden. -->
+    <DataTemplate x:Key="RosterRowTemplate" x:DataType="vm:ClassTeacherRosterRow">
+      <!-- Zwei Geschwister-Controls statt eines ContextMenu auf dem Zeilen-Button: Avalonia löst
+           $parent-Vorfahrenpfade in einem ContextMenu nicht zuverlässig auf, weil dessen Popup
+           nicht im normalen visuellen Baum unter dem ItemsControl hängt. Ein separater kleiner
+           Button daneben bleibt im normalen Baum und kann so ganz regulär auf das ViewModel des
+           ItemsControl zugreifen. -->
+      <Grid ColumnDefinitions="*,Auto">
+      <Button Grid.Column="0" Classes="rosterRow"
+              Command="{Binding $parent[ItemsControl].((vm:ClassTeacherOverviewViewModel)DataContext).ShowDetailsForStudentCommand}"
+              CommandParameter="{Binding}">
+        <Grid ColumnDefinitions="4,42,220,*,150,18">
+          <Border Grid.Column="0" Classes="statusFill"
+                  Classes.info="{Binding IsInfoStatus}"
+                  Classes.warning="{Binding IsWarningStatus}"
+                  Classes.danger="{Binding IsDangerStatus}"/>
+          <Border Grid.Column="1" Width="28" Height="28" CornerRadius="14"
+                  BorderBrush="{DynamicResource AppAvatarBorderBrush}" BorderThickness="1"
+                  HorizontalAlignment="Center" VerticalAlignment="Center"
+                  ToolTip.Tip="{Binding AbsenceTooltip}">
+            <TextBlock Text="{Binding Initials}" FontSize="10"
+                       HorizontalAlignment="Center" VerticalAlignment="Center"/>
+          </Border>
+          <TextBlock Grid.Column="2" Text="{Binding StudentName}" VerticalAlignment="Center"
+                     TextTrimming="CharacterEllipsis"/>
+          <StackPanel Grid.Column="3" VerticalAlignment="Center" Spacing="1"
+                      ToolTip.Tip="{Binding YearSummaryTooltip}">
+            <!-- Quick-Win Barrierefreiheit: Status nicht ausschließlich über Farbe, sondern auch
+                 über ein vorangestelltes Symbol bei Warnung/Gefahr (StatusTextWithGlyph). -->
+            <TextBlock Text="{Binding StatusTextWithGlyph}" Classes="status"
+                       Classes.info="{Binding IsInfoStatus}"
+                       Classes.warning="{Binding IsWarningStatus}"
+                       Classes.danger="{Binding IsDangerStatus}"
+                       FontSize="12" TextTrimming="CharacterEllipsis"/>
+            <!-- Fehlquote seit Schuljahresbeginn (Nutzer-Feedback: der Heute-Snapshot allein sagt
+                 für Zeugnis/Attestpflicht wenig aus) — als dezente zweite Zeile statt eigener
+                 Spalte, damit das bestehende Layout nicht neu vermessen werden muss. -->
+            <TextBlock Text="{Binding YearSummaryLabel}" IsVisible="{Binding HasYearSummary}"
+                       FontSize="10" Opacity="0.5" TextTrimming="CharacterEllipsis"/>
+          </StackPanel>
+          <TextBlock Grid.Column="4" Text="{Binding ClassRegisterLabel}"
+                     Foreground="{DynamicResource AppAccentTextBrush}"
+                     VerticalAlignment="Center" FontSize="11"/>
+          <TextBlock Grid.Column="5" Text="›" FontSize="18" Opacity="0.7" VerticalAlignment="Center"/>
+        </Grid>
+      </Button>
+      <!-- Quick-Win: "Eltern kontaktieren" als vorbefüllte Wiedervorlage direkt aus der Zeile
+           anlegen, statt erst ins Aufgaben-Modul zu wechseln und von Hand einzutragen. -->
+      <Button Grid.Column="1" Classes="rosterRowAction" Content="+"
+              ToolTip.Tip="Wiedervorlage „Eltern kontaktieren&#8220; anlegen"
+              Command="{Binding $parent[ItemsControl].((vm:ClassTeacherOverviewViewModel)DataContext).CreateReminderForStudentCommand}"
+              CommandParameter="{Binding}"/>
+      </Grid>
+    </DataTemplate>
+  </UserControl.Resources>
+
+  <Grid>
+    <StackPanel IsVisible="{Binding !HomeroomClassConfigured}" HorizontalAlignment="Center"
+                VerticalAlignment="Center" Spacing="12" MaxWidth="380">
+      <Border Width="56" Height="56" CornerRadius="28" HorizontalAlignment="Center"
+              Background="{DynamicResource AppAccentSoftBackgroundBrush}">
+        <TextBlock Text="KL" FontSize="18" FontWeight="Bold"
+                   Foreground="{DynamicResource AppAccentOnSoftBrush}"
+                   HorizontalAlignment="Center" VerticalAlignment="Center"/>
+      </Border>
+      <TextBlock Text="Noch keine Klasse ausgewählt" FontSize="18" FontWeight="SemiBold" HorizontalAlignment="Center"/>
+      <TextBlock TextWrapping="Wrap" TextAlignment="Center" FontSize="13" Opacity="0.65"
+                 Text="Wähle in den WebUntis-Einstellungen die Klasse aus, deren Klassenlehrer/-in du bist."/>
+      <Button Content="Zu den Einstellungen" Command="{Binding GoToSettingsCommand}" HorizontalAlignment="Center"/>
+    </StackPanel>
+
+    <TabbedPage IsVisible="{Binding HomeroomClassConfigured}" TabPlacement="Top"
+                SelectedIndex="{Binding ActiveTabIndex, Mode=TwoWay}">
+      <ContentPage Header="Übersicht">
+        <Grid RowDefinitions="Auto,Auto,*" Margin="16,12,16,16" RowSpacing="10">
+          <Grid Grid.Row="0" ColumnDefinitions="*,Auto">
+            <StackPanel Grid.Column="0" Spacing="2">
+              <TextBlock Text="{Binding HomeroomClassName, StringFormat='Klasse {0}'}"
+                         FontSize="24" FontWeight="SemiBold"/>
+              <TextBlock Text="Klassenlehrer-Übersicht" FontSize="13" Opacity="0.58"/>
+            </StackPanel>
+            <StackPanel Grid.Column="1" Orientation="Horizontal" Spacing="10" VerticalAlignment="Center">
+              <TextBlock Text="{Binding LastUpdatedLabel}" FontSize="11" Opacity="0.55" VerticalAlignment="Center"/>
+              <Button Content="↻  Aktualisieren" Command="{Binding LoadCommand}" IsEnabled="{Binding !Busy}"
+                      Background="Transparent" BorderThickness="0"
+                      Foreground="{DynamicResource AppAccentTextBrush}"/>
+            </StackPanel>
+          </Grid>
+
+          <Grid Grid.Row="1" ColumnDefinitions="*,*,*,*">
+            <Border Grid.Column="0" Classes="metric">
+              <Grid ColumnDefinitions="36,*">
+                <TextBlock Text="◉" FontSize="22" VerticalAlignment="Center"
+                           Foreground="{DynamicResource AppStatusInfoBrush}"/>
+                <StackPanel Grid.Column="1"><TextBlock Text="{Binding StudentCount}" FontSize="22" FontWeight="SemiBold"/><TextBlock Text="Schüler*innen" FontSize="11" Opacity="0.6"/></StackPanel>
+              </Grid>
+            </Border>
+            <Border Grid.Column="1" Classes="metric">
+              <Grid ColumnDefinitions="36,*">
+                <TextBlock Text="△" FontSize="24" VerticalAlignment="Center"
+                           Foreground="{DynamicResource AppStatusWarningBrush}"/>
+                <StackPanel Grid.Column="1"><TextBlock Text="{Binding TodayAlertCount}" FontSize="22" FontWeight="SemiBold"/><TextBlock Text="heute auffällig" FontSize="11" Opacity="0.6"/></StackPanel>
+              </Grid>
+            </Border>
+            <Border Grid.Column="2" Classes="metric">
+              <Grid ColumnDefinitions="36,*">
+                <TextBlock Text="!" FontSize="22" VerticalAlignment="Center"
+                           Foreground="{DynamicResource AppStatusDangerBrush}"/>
+                <StackPanel Grid.Column="1"><TextBlock Text="{Binding TodayUnexcusedCount}" FontSize="22" FontWeight="SemiBold"/><TextBlock Text="{Binding TodayUnexcusedSummaryLabel}" FontSize="11" Opacity="0.6"/></StackPanel>
+              </Grid>
+            </Border>
+            <Border Grid.Column="3" Classes="metric" Margin="0">
+              <Grid ColumnDefinitions="36,*">
+                <TextBlock Text="▤" FontSize="21" VerticalAlignment="Center"
+                           Foreground="{DynamicResource AppStatusInfoBrush}"/>
+                <StackPanel Grid.Column="1"><TextBlock Text="{Binding RecentClassRegisterCount}" FontSize="22" FontWeight="SemiBold"/><TextBlock Text="Klassenbucheinträge · 7 Tage" FontSize="11" Opacity="0.6"/></StackPanel>
+              </Grid>
+            </Border>
+          </Grid>
+
+          <Grid Grid.Row="2" ColumnDefinitions="*,286" ColumnSpacing="12">
+            <Grid Grid.Column="0" RowDefinitions="Auto,*">
+              <Border Grid.Row="0" Background="{DynamicResource AppCardBackgroundBrush}"
+                      BorderBrush="{DynamicResource AppCardBorderBrush}" BorderThickness="1"
+                      CornerRadius="8" Padding="8" Margin="0,0,0,4">
+                <Grid ColumnDefinitions="Auto,Auto,Auto,*,250" ColumnSpacing="8">
+                  <Button Grid.Column="0" Classes="filter" Classes.active="{Binding AlertsFilterSelected}"
+                          Content="Auffällig" Command="{Binding ShowAlertsCommand}"/>
+                  <Button Grid.Column="1" Classes="filter" Classes.active="{Binding ClassRegisterFilterSelected}"
+                          Content="Klassenbuch" Command="{Binding ShowClassRegisterCommand}"/>
+                  <Button Grid.Column="2" Classes="filter" Classes.active="{Binding AllFilterSelected}"
+                          Content="Alle" Command="{Binding ShowAllCommand}"/>
+                  <TextBox Grid.Column="4" Text="{Binding SearchText, Mode=TwoWay}" PlaceholderText="Schüler*in suchen…"
+                           FontSize="12" MinHeight="32"/>
+                </Grid>
+              </Border>
+              <ScrollViewer Grid.Row="1">
+                <StackPanel>
+                  <TextBlock Classes="sectionLabel" Text="{Binding PrimarySectionTitle}" IsVisible="{Binding HasPrimaryRoster}"/>
+                  <ItemsControl ItemsSource="{Binding PrimaryRoster}" ItemTemplate="{StaticResource RosterRowTemplate}"/>
+
+                  <TextBlock Classes="sectionLabel" Text="{Binding SecondarySectionTitle}" IsVisible="{Binding HasSecondaryRoster}"/>
+                  <ItemsControl ItemsSource="{Binding SecondaryRoster}" ItemTemplate="{StaticResource RosterRowTemplate}"/>
+
+                  <StackPanel IsVisible="{Binding HasNoFilterResults}" HorizontalAlignment="Center" Margin="0,54,0,0" Spacing="6">
+                    <TextBlock Text="Keine passenden Schüler*innen" FontWeight="SemiBold" HorizontalAlignment="Center"/>
+                    <TextBlock Text="Passe Filter oder Suche an." FontSize="12" Opacity="0.55"/>
+                  </StackPanel>
+                </StackPanel>
+              </ScrollViewer>
+            </Grid>
+
+            <ScrollViewer Grid.Column="1">
+              <StackPanel>
+                <Border Classes="sidePanel">
+                  <StackPanel Spacing="9">
+                    <TextBlock Text="Tagesüberblick" FontSize="14" FontWeight="SemiBold"/>
+                    <!-- Quick-Win: ein gestapelter 100-%-Balken statt vier Einzelzeilen mit
+                         separater Prozentspalte — Verteilung auf einen Blick statt aus vier
+                         Prozentzahlen erschlossen. Jedes Segment multipliziert per MultiBinding
+                         die gerenderte Breite der Track-Leiste (x:Name="DayOverviewTrack") mit
+                         seinem Anteil 0…1 (FractionWidthConverter) — bleibt dadurch korrekt, egal
+                         wie breit die Seitenspalte in XAML gerade ist.
+                         Reihenfolge Ok→Info→Warnung→Gefahr (nicht Ok→Warnung→Info→Gefahr):
+                         Grün und das validierte Dunkel-Gelb liegen unter Protanopie zu nah
+                         beieinander (ΔE 3.0), direkt benachbart wäre das dieselbe Verwechslung
+                         wie beim ursprünglichen Nutzer-Feedback zu Warnung/Gefahr. Mit Info
+                         dazwischen entspricht die Reihenfolge zudem der echten Dringlichkeit
+                         (siehe ClassTeacherRosterRow.AttentionRank: Gefahr > Warnung > Info > Ok). -->
+                    <Grid Height="10" ToolTip.Tip="{Binding DayOverviewTooltip}">
+                      <Border x:Name="DayOverviewTrack" Background="{DynamicResource AppTrackBackgroundBrush}"
+                              CornerRadius="5"/>
+                      <Border CornerRadius="5" ClipToBounds="True" HorizontalAlignment="Left">
+                        <StackPanel Orientation="Horizontal">
+                          <Border Classes="statusFill">
+                            <Border.Width>
+                              <MultiBinding Converter="{x:Static conv:FractionWidthConverter.Instance}">
+                                <Binding ElementName="DayOverviewTrack" Path="Bounds.Width"/>
+                                <Binding Path="PresentFraction"/>
+                              </MultiBinding>
+                            </Border.Width>
+                          </Border>
+                          <Border Classes="statusFill info">
+                            <Border.Width>
+                              <MultiBinding Converter="{x:Static conv:FractionWidthConverter.Instance}">
+                                <Binding ElementName="DayOverviewTrack" Path="Bounds.Width"/>
+                                <Binding Path="ExcusedAbsenceFraction"/>
+                              </MultiBinding>
+                            </Border.Width>
+                          </Border>
+                          <Border Classes="statusFill warning">
+                            <Border.Width>
+                              <MultiBinding Converter="{x:Static conv:FractionWidthConverter.Instance}">
+                                <Binding ElementName="DayOverviewTrack" Path="Bounds.Width"/>
+                                <Binding Path="LateFraction"/>
+                              </MultiBinding>
+                            </Border.Width>
+                          </Border>
+                          <Border Classes="statusFill danger">
+                            <Border.Width>
+                              <MultiBinding Converter="{x:Static conv:FractionWidthConverter.Instance}">
+                                <Binding ElementName="DayOverviewTrack" Path="Bounds.Width"/>
+                                <Binding Path="UnexcusedAbsenceFraction"/>
+                              </MultiBinding>
+                            </Border.Width>
+                          </Border>
+                        </StackPanel>
+                      </Border>
+                    </Grid>
+                    <StackPanel Spacing="5">
+                      <StackPanel Orientation="Horizontal" Spacing="6"><Border Width="7" Height="7" CornerRadius="4" Classes="statusFill"/><TextBlock Text="{Binding PresentSummaryLabel}" FontSize="12"/></StackPanel>
+                      <StackPanel Orientation="Horizontal" Spacing="6"><Border Width="7" Height="7" CornerRadius="4" Classes="statusFill info"/><TextBlock Text="{Binding ExcusedAbsenceSummaryLabel}" FontSize="12"/></StackPanel>
+                      <StackPanel Orientation="Horizontal" Spacing="6"><Border Width="7" Height="7" CornerRadius="4" Classes="statusFill warning"/><TextBlock Text="{Binding LateSummaryLabel}" FontSize="12"/></StackPanel>
+                      <StackPanel Orientation="Horizontal" Spacing="6"><Border Width="7" Height="7" CornerRadius="4" Classes="statusFill danger"/><TextBlock Text="{Binding UnexcusedAbsenceSummaryLabel}" FontSize="12"/></StackPanel>
+                    </StackPanel>
+                  </StackPanel>
+                </Border>
+
+                <Border Classes="sidePanel">
+                  <StackPanel Spacing="8">
+                    <TextBlock Text="Trend · letzte 7 Tage" FontSize="14" FontWeight="SemiBold"/>
+                    <ItemsControl ItemsSource="{Binding TrendDays}">
+                      <ItemsControl.ItemTemplate>
+                        <DataTemplate x:DataType="vm:ClassTeacherTrendDay">
+                          <Grid ColumnDefinitions="42,*,24" Margin="0,2">
+                            <TextBlock Text="{Binding DayLabel}" FontSize="11" Opacity="0.6" VerticalAlignment="Center"/>
+                            <Grid Grid.Column="1" Height="8" VerticalAlignment="Center"
+                                  ToolTip.Tip="{Binding DetailTooltip}">
+                              <Border x:Name="TrendTrack" Background="{DynamicResource AppTrackBackgroundBrush}"
+                                      CornerRadius="4"/>
+                              <!-- Gestapelter Balken: drei sich nicht überschneidende Segmente
+                                   (siehe ClassTeacherTrendDay). Jedes Segment multipliziert per
+                                   MultiBinding die gerenderte Breite von "TrendTrack" mit seinem
+                                   Anteil 0…1 (FractionWidthConverter) — bleibt damit auch dann
+                                   korrekt proportional, wenn die Seitenspalte in XAML mal eine
+                                   andere Breite bekommt. Der äußere Wrapper ist auf CornerRadius
+                                   zugeschnitten, damit nur die äußeren Kanten rund sind, nicht
+                                   jedes Segment einzeln. -->
+                              <Border CornerRadius="4" ClipToBounds="True" HorizontalAlignment="Left">
+                                <Border.Width>
+                                  <MultiBinding Converter="{x:Static conv:FractionWidthConverter.Instance}">
+                                    <Binding ElementName="TrendTrack" Path="Bounds.Width"/>
+                                    <Binding Path="TotalFraction"/>
+                                  </MultiBinding>
+                                </Border.Width>
+                                <StackPanel Orientation="Horizontal">
+                                  <Border Classes="statusFill danger">
+                                    <Border.Width>
+                                      <MultiBinding Converter="{x:Static conv:FractionWidthConverter.Instance}">
+                                        <Binding ElementName="TrendTrack" Path="Bounds.Width"/>
+                                        <Binding Path="UnexcusedFraction"/>
+                                      </MultiBinding>
+                                    </Border.Width>
+                                  </Border>
+                                  <Border Classes="statusFill warning">
+                                    <Border.Width>
+                                      <MultiBinding Converter="{x:Static conv:FractionWidthConverter.Instance}">
+                                        <Binding ElementName="TrendTrack" Path="Bounds.Width"/>
+                                        <Binding Path="LateExcusedFraction"/>
+                                      </MultiBinding>
+                                    </Border.Width>
+                                  </Border>
+                                  <Border Classes="statusFill info">
+                                    <Border.Width>
+                                      <MultiBinding Converter="{x:Static conv:FractionWidthConverter.Instance}">
+                                        <Binding ElementName="TrendTrack" Path="Bounds.Width"/>
+                                        <Binding Path="ExcusedFraction"/>
+                                      </MultiBinding>
+                                    </Border.Width>
+                                  </Border>
+                                </StackPanel>
+                              </Border>
+                            </Grid>
+                            <TextBlock Grid.Column="2" Text="{Binding AlertCount}" FontSize="11" HorizontalAlignment="Right"/>
+                          </Grid>
+                        </DataTemplate>
+                      </ItemsControl.ItemTemplate>
+                    </ItemsControl>
+                    <StackPanel Orientation="Horizontal" Spacing="10">
+                      <StackPanel Orientation="Horizontal" Spacing="4">
+                        <Border Width="7" Height="7" CornerRadius="4" Classes="statusFill danger"/>
+                        <TextBlock Text="Unentsch." FontSize="10" Opacity="0.55"/>
+                      </StackPanel>
+                      <StackPanel Orientation="Horizontal" Spacing="4">
+                        <Border Width="7" Height="7" CornerRadius="4" Classes="statusFill warning"/>
+                        <TextBlock Text="Verspätet" FontSize="10" Opacity="0.55"/>
+                      </StackPanel>
+                      <StackPanel Orientation="Horizontal" Spacing="4">
+                        <Border Width="7" Height="7" CornerRadius="4" Classes="statusFill info"/>
+                        <TextBlock Text="Entschuldigt" FontSize="10" Opacity="0.55"/>
+                      </StackPanel>
+                    </StackPanel>
+                  </StackPanel>
+                </Border>
+
+                <Border Classes="sidePanel" IsVisible="{Binding HasOpenExcuses}">
+                  <StackPanel Spacing="8">
+                    <TextBlock Text="Offene Entschuldigungen" FontSize="14" FontWeight="SemiBold"/>
+                    <ItemsControl ItemsSource="{Binding OpenExcuses}">
+                      <ItemsControl.ItemTemplate>
+                        <DataTemplate x:DataType="vm:ClassTeacherOpenExcuseRow">
+                          <Grid ColumnDefinitions="*,Auto">
+                          <Button Grid.Column="0" Classes="rosterRow" Padding="6,5"
+                                  Command="{Binding $parent[ItemsControl].((vm:ClassTeacherOverviewViewModel)DataContext).ShowDetailsForOpenExcuseCommand}"
+                                  CommandParameter="{Binding}">
+                            <Grid ColumnDefinitions="4,*,Auto" Margin="0,2">
+                              <Border Grid.Column="0" CornerRadius="2" Margin="0,1,8,1"
+                                      Classes="statusFill" Classes.warning="{Binding !IsOverdue}"
+                                      Classes.danger="{Binding IsOverdue}"/>
+                              <StackPanel Grid.Column="1">
+                                <TextBlock Text="{Binding StudentName}" FontSize="12" FontWeight="SemiBold"/>
+                                <TextBlock Text="{Binding DaysOpenLabel}" FontSize="11" Opacity="0.62"/>
+                              </StackPanel>
+                              <TextBlock Grid.Column="2" Text="{Binding DateLabel}" FontSize="11"
+                                         Opacity="0.5" VerticalAlignment="Center"/>
+                            </Grid>
+                          </Button>
+                          <Button Grid.Column="1" Classes="rosterRowAction" Content="+"
+                                  ToolTip.Tip="Wiedervorlage „Eltern kontaktieren&#8220; anlegen"
+                                  Command="{Binding $parent[ItemsControl].((vm:ClassTeacherOverviewViewModel)DataContext).CreateReminderForOpenExcuseCommand}"
+                                  CommandParameter="{Binding}"/>
+                          </Grid>
+                        </DataTemplate>
+                      </ItemsControl.ItemTemplate>
+                    </ItemsControl>
+                    <TextBlock FontSize="11" Opacity="0.5" IsVisible="{Binding HasOpenExcuseOverflow}">
+                      <Run Text="+"/><Run Text="{Binding OpenExcuseOverflowCount}"/><Run Text=" weitere"/>
+                    </TextBlock>
+                  </StackPanel>
+                </Border>
+
+                <Border Classes="sidePanel" IsVisible="{Binding HasPatternNotices}">
+                  <StackPanel Spacing="8">
+                    <TextBlock Text="Muster erkannt" FontSize="14" FontWeight="SemiBold"/>
+                    <ItemsControl ItemsSource="{Binding PatternNotices}">
+                      <ItemsControl.ItemTemplate>
+                        <DataTemplate x:DataType="vm:ClassTeacherPatternNotice">
+                          <Grid ColumnDefinitions="4,*" Margin="0,3">
+                            <Border CornerRadius="2" Margin="0,1,8,1" Classes="statusFill"
+                                    Classes.info="{Binding IsInfoStatus}"
+                                    Classes.warning="{Binding IsWarningStatus}"
+                                    Classes.danger="{Binding IsDangerStatus}"/>
+                            <StackPanel Grid.Column="1">
+                              <TextBlock Text="{Binding StudentName}" FontSize="12" FontWeight="SemiBold"/>
+                              <TextBlock Text="{Binding Message}" FontSize="11" Opacity="0.62" TextWrapping="Wrap"/>
+                            </StackPanel>
+                          </Grid>
+                        </DataTemplate>
+                      </ItemsControl.ItemTemplate>
+                    </ItemsControl>
+                  </StackPanel>
+                </Border>
+
+                <Border Classes="sidePanel">
+                  <StackPanel Spacing="8">
+                    <TextBlock Text="Nächste Schritte" FontSize="14" FontWeight="SemiBold"/>
+                    <Button Content="Klassenbuch öffnen" Command="{Binding OpenClassRegisterCommand}" HorizontalAlignment="Stretch"/>
+                    <Button Content="Fehlzeiten öffnen" Command="{Binding OpenAbsencesCommand}" HorizontalAlignment="Stretch"/>
+                    <Button Content="Aufgaben &amp; Wiedervorlagen" Command="{Binding GoToWorkloadCommand}"
+                            HorizontalAlignment="Stretch" Background="Transparent"/>
+                  </StackPanel>
+                </Border>
+                <TextBlock Text="{Binding Status}" FontSize="11" TextWrapping="Wrap" Opacity="0.6"/>
+              </StackPanel>
+            </ScrollViewer>
+          </Grid>
+        </Grid>
+      </ContentPage>
+
+      <ContentPage Header="Klassenbuch">
+        <views:ClassTeacherRegisterView DataContext="{Binding DetailsTab}"/>
+      </ContentPage>
+      <ContentPage Header="Fehlzeiten">
+        <views:ClassTeacherAbsencesView DataContext="{Binding DetailsTab}"/>
+      </ContentPage>
+    </TabbedPage>
+  </Grid>
+</UserControl>

LehrerApp.Desktop/Views/ClassTeacher/ClassTeacherOverviewView.axaml.cs

@@ -0,0 +1,8 @@
+using Avalonia.Controls;
+
+namespace LehrerApp.Desktop.Views.ClassTeacher;
+
+public partial class ClassTeacherOverviewView : UserControl
+{
+    public ClassTeacherOverviewView() => InitializeComponent();
+}

LehrerApp.Desktop/Views/ClassTeacher/ClassTeacherRegisterView.axaml

@@ -0,0 +1,110 @@
+<UserControl xmlns="https://github.com/avaloniaui"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:vm="clr-namespace:LehrerApp.Desktop.ViewModels.ClassTeacher"
+             x:Class="LehrerApp.Desktop.Views.ClassTeacher.ClassTeacherRegisterView"
+             x:DataType="vm:ClassTeacherDetailsViewModel">
+
+  <UserControl.Styles>
+    <!-- Siehe Styles/SemanticBrushes.axaml: Farben per DynamicResource, damit der Theme-Wechsel
+         sie live austauscht; die Statusfarbe je Zeile kommt als Style-Klasse aus dem ViewModel. -->
+    <Style Selector="Border.filterCard">
+      <Setter Property="Background" Value="{DynamicResource AppCardBackgroundBrush}"/>
+      <Setter Property="BorderBrush" Value="{DynamicResource AppCardBorderBrush}"/>
+      <Setter Property="BorderThickness" Value="1"/>
+      <Setter Property="CornerRadius" Value="8"/>
+      <Setter Property="Padding" Value="10"/>
+    </Style>
+    <Style Selector="TextBlock.status">
+      <Setter Property="Foreground" Value="{DynamicResource AppStatusOkBrush}"/>
+    </Style>
+    <Style Selector="TextBlock.status.info">
+      <Setter Property="Foreground" Value="{DynamicResource AppStatusInfoBrush}"/>
+    </Style>
+    <Style Selector="TextBlock.status.warning">
+      <Setter Property="Foreground" Value="{DynamicResource AppStatusWarningBrush}"/>
+    </Style>
+    <Style Selector="TextBlock.status.danger">
+      <Setter Property="Foreground" Value="{DynamicResource AppStatusDangerBrush}"/>
+    </Style>
+  </UserControl.Styles>
+
+  <Grid RowDefinitions="Auto,Auto,Auto,*,Auto" Margin="16" RowSpacing="10">
+    <Grid Grid.Row="0" ColumnDefinitions="*,Auto">
+      <StackPanel>
+        <TextBlock Text="Klassenbucheinträge" FontSize="22" FontWeight="SemiBold"/>
+        <TextBlock Text="Einträge anderer Lehrkräfte – nur zur Ansicht" FontSize="12" Opacity="0.55"/>
+      </StackPanel>
+      <Button Grid.Column="1" Content="↻  Aus WebUntis aktualisieren" Command="{Binding RefreshCommand}"
+              IsEnabled="{Binding !Busy}" Background="Transparent" Foreground="{DynamicResource AppAccentTextBrush}" VerticalAlignment="Center"/>
+    </Grid>
+
+    <Border Grid.Row="1" Classes="filterCard">
+      <Grid RowDefinitions="Auto,Auto" RowSpacing="8">
+        <Grid Grid.Row="0" ColumnDefinitions="155,Auto,*,Auto,*" ColumnSpacing="8">
+          <ComboBox Grid.Column="0" SelectedIndex="{Binding QuickRangeIndex, Mode=TwoWay}">
+            <ComboBoxItem Content="Heute"/><ComboBoxItem Content="Letzte 7 Tage"/><ComboBoxItem Content="Letzte 30 Tage"/>
+          </ComboBox>
+          <TextBlock Grid.Column="1" Text="von" VerticalAlignment="Center" Opacity="0.6"/>
+          <DatePicker Grid.Column="2" SelectedDate="{Binding StartDate}" HorizontalAlignment="Stretch"/>
+          <TextBlock Grid.Column="3" Text="bis" VerticalAlignment="Center" Opacity="0.6"/>
+          <DatePicker Grid.Column="4" SelectedDate="{Binding EndDate}" HorizontalAlignment="Stretch"/>
+        </Grid>
+        <Grid Grid.Row="1" ColumnDefinitions="*,Auto,Auto" ColumnSpacing="8">
+          <TextBox Grid.Column="0" Text="{Binding StudentFilter, Mode=TwoWay}" PlaceholderText="Schüler*in filtern…"/>
+          <Button Grid.Column="1" Content="Anzeigen" Command="{Binding ApplyFilterCommand}" IsEnabled="{Binding !Busy}"/>
+          <Button Grid.Column="2" Content="Filter löschen" Command="{Binding ClearStudentFilterCommand}"
+                  IsVisible="{Binding StudentFilter, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"/>
+        </Grid>
+      </Grid>
+    </Border>
+
+    <!-- Nutzer-Feedback: die reine Gesamtzahl der Einträge sagt wenig, eine Aufschlüsselung nach
+         Kategorie ("Hausaufgaben fehlen: 12× — 5× Ben Schmidt, 3× Ada Müller") ist die eigentlich
+         interessante Information. Als Chip-Reihe statt eigener Spalte in der Tabelle, damit die
+         bestehenden Spalten unangetastet bleiben. -->
+    <Border Grid.Row="2" Classes="filterCard" IsVisible="{Binding HasCategoryAggregates}">
+      <StackPanel Spacing="6">
+        <TextBlock Text="Kategorien im Zeitraum" FontSize="12" FontWeight="SemiBold" Opacity="0.7"/>
+        <ItemsControl ItemsSource="{Binding CategoryAggregates}">
+          <ItemsControl.ItemsPanel>
+            <ItemsPanelTemplate>
+              <WrapPanel/>
+            </ItemsPanelTemplate>
+          </ItemsControl.ItemsPanel>
+          <ItemsControl.ItemTemplate>
+            <DataTemplate x:DataType="vm:ClassTeacherCategoryAggregateRow">
+              <Border Background="{DynamicResource AppChipBackgroundBrush}" CornerRadius="5"
+                      Padding="8,4" Margin="0,0,6,6">
+                <StackPanel Orientation="Horizontal" Spacing="4">
+                  <TextBlock Text="{Binding CategoryName}" FontSize="11" FontWeight="SemiBold"/>
+                  <TextBlock Text="{Binding SummaryLabel}" FontSize="11" Opacity="0.6"/>
+                </StackPanel>
+              </Border>
+            </DataTemplate>
+          </ItemsControl.ItemTemplate>
+        </ItemsControl>
+      </StackPanel>
+    </Border>
+
+    <Grid Grid.Row="3">
+      <DataGrid ItemsSource="{Binding Entries}" AutoGenerateColumns="False" IsReadOnly="True"
+                GridLinesVisibility="Horizontal" BorderBrush="{DynamicResource AppCardBorderBrush}" BorderThickness="1"
+                CanUserResizeColumns="True" CanUserSortColumns="True" RowHeight="46">
+        <DataGrid.Columns>
+          <DataGridTextColumn Header="Datum" Binding="{Binding DateLabel}" Width="105"/>
+          <DataGridTextColumn Header="Schüler*in" Binding="{Binding StudentDisplayName}" Width="1.25*"/>
+          <DataGridTextColumn Header="Fach" Binding="{Binding Subject}" Width="0.7*"/>
+          <DataGridTextColumn Header="Lehrkraft" Binding="{Binding TeacherUsername}" Width="0.8*"/>
+          <DataGridTextColumn Header="Kategorie" Binding="{Binding CategoryName}" Width="1*"/>
+          <DataGridTextColumn Header="Gruppe" Binding="{Binding CategoryGroup}" Width="0.8*"/>
+          <DataGridTextColumn Header="Eintrag" Binding="{Binding Text}" Width="2*"/>
+        </DataGrid.Columns>
+      </DataGrid>
+      <StackPanel IsVisible="{Binding !HasEntries}" HorizontalAlignment="Center" VerticalAlignment="Center" Spacing="5">
+        <TextBlock Text="Keine Klassenbucheinträge im gewählten Zeitraum" FontWeight="SemiBold"/>
+        <TextBlock Text="Passe Zeitraum oder Schülerfilter an." FontSize="12" Opacity="0.55"/>
+      </StackPanel>
+    </Grid>
+    <TextBlock Grid.Row="4" Text="{Binding Status}" FontSize="11" Opacity="0.6"/>
+  </Grid>
+</UserControl>

LehrerApp.Desktop/Views/ClassTeacher/ClassTeacherRegisterView.axaml.cs

@@ -0,0 +1,8 @@
+using Avalonia.Controls;
+
+namespace LehrerApp.Desktop.Views.ClassTeacher;
+
+public partial class ClassTeacherRegisterView : UserControl
+{
+    public ClassTeacherRegisterView() => InitializeComponent();
+}

LehrerApp.Desktop/Views/Dashboard/DashboardView.axaml

@@ -25,10 +25,40 @@
           <TextBlock Text="{Binding Greeting}" FontSize="14" Opacity="0.6"/>
           <TextBlock Text="{Binding CurrentDate}" FontSize="24" FontWeight="SemiBold"/>
         </StackPanel>
-        <Button Grid.Column="1" Content="Dashboard anpassen" Command="{Binding ToggleDashboardSettingsCommand}"
+        <StackPanel Grid.Column="1" Orientation="Horizontal" Spacing="8">
-                VerticalAlignment="Center"/>
+          <Button Content="Klassenbuch abgleichen…" Click="OnCompareWebUntisDocumentationClick"
+                  VerticalAlignment="Center"/>
+          <Button Content="Bereiche anpassen" Command="{Binding ToggleDashboardSettingsCommand}"
+                  VerticalAlignment="Center"/>
+        </StackPanel>
       </Grid>
 
+      <!-- Der Tagesfokus beantwortet zuerst die vier Fragen, die beim Öffnen der App zählen:
+           Was unterrichte ich, was ist zu tun, wo muss ich reagieren und was steht an? -->
+      <Border Background="{DynamicResource AppCardBackgroundBrush}"
+              BorderBrush="{DynamicResource AppCardBorderBrush}" BorderThickness="1"
+              CornerRadius="10" Padding="16,14">
+        <Grid ColumnDefinitions="*,*,*,*">
+          <StackPanel Grid.Column="0" Spacing="3">
+            <TextBlock Text="UNTERRICHT HEUTE" FontSize="10" FontWeight="Bold" Opacity="0.5"/>
+            <TextBlock Text="{Binding TodayLessonSummary}" FontSize="18" FontWeight="SemiBold"/>
+          </StackPanel>
+          <StackPanel Grid.Column="1" Spacing="3" Margin="18,0,0,0">
+            <TextBlock Text="AUFGABEN" FontSize="10" FontWeight="Bold" Opacity="0.5"/>
+            <TextBlock Text="{Binding OpenTaskSummary}" FontSize="18" FontWeight="SemiBold"/>
+          </StackPanel>
+          <StackPanel Grid.Column="2" Spacing="3" Margin="18,0,0,0">
+            <TextBlock Text="HANDLUNGSBEDARF" FontSize="10" FontWeight="Bold" Opacity="0.5"/>
+            <TextBlock Text="{Binding AttentionSummary}" FontSize="18" FontWeight="SemiBold"
+                       Foreground="{DynamicResource AppStatusWarningBrush}"/>
+          </StackPanel>
+          <StackPanel Grid.Column="3" Spacing="3" Margin="18,0,0,0">
+            <TextBlock Text="NÄCHSTE 30 TAGE" FontSize="10" FontWeight="Bold" Opacity="0.5"/>
+            <TextBlock Text="{Binding UpcomingSummary}" FontSize="18" FontWeight="SemiBold"/>
+          </StackPanel>
+        </Grid>
+      </Border>
+
       <Border Background="{DynamicResource SystemControlBackgroundAltHighBrush}" CornerRadius="8"
               Padding="12" IsVisible="{Binding IsDashboardSettingsOpen}">
         <ItemsControl ItemsSource="{Binding DashboardCards}">
@@ -55,14 +85,15 @@
       </Border>
 
       <!-- Serverseitig gecachte DWD-Daten für den in den Einstellungen hinterlegten Schulstandort. -->
-      <Border Background="{DynamicResource SystemControlBackgroundAltHighBrush}" CornerRadius="8"
+      <Expander Header="{Binding WeatherSummary}" IsExpanded="{Binding HasWeatherWarnings}"
-              Padding="16" IsVisible="{Binding IsWeatherPanelVisible}">
+                IsVisible="{Binding IsWeatherPanelVisible}"
-        <StackPanel Spacing="10">
+                Background="{DynamicResource AppCardBackgroundBrush}"
+                BorderBrush="{DynamicResource AppCardBorderBrush}" BorderThickness="1"
+                CornerRadius="8" Padding="12,6">
+        <StackPanel Spacing="10" Margin="6,8,6,6">
           <Grid ColumnDefinitions="*,Auto">
             <StackPanel>
               <TextBlock Text="WETTER AM SCHULSTANDORT" FontSize="11" FontWeight="Bold" Opacity="0.5"/>
-              <TextBlock Text="{Binding WeatherSummary}" FontSize="20" FontWeight="SemiBold" Margin="0,5,0,0"
-                         IsVisible="{Binding WeatherSummary, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"/>
               <TextBlock Text="{Binding WeatherDetails}" FontSize="11" Opacity="0.65" TextWrapping="Wrap"
                          IsVisible="{Binding WeatherDetails, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"/>
             </StackPanel>
@@ -92,17 +123,20 @@
           </ItemsControl>
           <TextBlock Text="Wetterdaten © Deutscher Wetterdienst" FontSize="10" Opacity="0.5"/>
         </StackPanel>
-      </Border>
+      </Expander>
 
-      <Grid ColumnDefinitions="*,*" RowDefinitions="Auto,Auto,Auto,Auto,Auto,Auto">
+      <TextBlock Text="HEUTE UND HANDLUNGSBEDARF" FontSize="11" FontWeight="Bold" Opacity="0.5"
+                 Margin="2,2,0,-8"/>
+
+      <Grid ColumnDefinitions="3*,2*" RowDefinitions="Auto,Auto,Auto,Auto,Auto,Auto">
 
         <!-- Heutige Stunden -->
         <Border Grid.Column="{Binding TodayCard.Column}" Grid.Row="{Binding TodayCard.Row}"
-                IsVisible="{Binding TodayCard.IsVisible}" Margin="0,0,8,8"
+                IsVisible="{Binding TodayCard.EffectiveIsVisible}" Margin="0,0,8,8"
                 Background="{DynamicResource SystemControlBackgroundAltHighBrush}"
                 CornerRadius="8" Padding="16">
           <StackPanel>
-            <TextBlock Text="HEUTE" FontSize="11" FontWeight="Bold"
+            <TextBlock Text="Heute" FontSize="14" FontWeight="SemiBold"
                        Opacity="0.5" Margin="0,0,0,10"/>
             <ItemsControl ItemsSource="{Binding TodaysLessons}">
               <ItemsControl.ItemTemplate>
@@ -139,12 +173,12 @@
 
         <!-- Offene Aufgaben -->
         <Border Grid.Column="{Binding TasksCard.Column}" Grid.Row="{Binding TasksCard.Row}"
-                IsVisible="{Binding TasksCard.IsVisible}" Margin="8,0,0,8"
+                IsVisible="{Binding TasksCard.EffectiveIsVisible}" Margin="8,0,0,8"
                 Background="{DynamicResource SystemControlBackgroundAltHighBrush}"
                 CornerRadius="8" Padding="16">
           <StackPanel>
             <Grid ColumnDefinitions="*,Auto,Auto" Margin="0,0,0,10">
-              <TextBlock Grid.Column="0" Text="OFFENE AUFGABEN" FontSize="11" FontWeight="Bold"
+              <TextBlock Grid.Column="0" Text="Offene Aufgaben" FontSize="14" FontWeight="SemiBold"
                          Opacity="0.5" VerticalAlignment="Center"/>
               <Button Grid.Column="1" Content="🔔＋" FontSize="12" Padding="7,2" Margin="0,0,4,0"
                       ToolTip.Tip="Erinnerung anlegen" Command="{Binding AddReminderCommand}"/>
@@ -176,7 +210,7 @@
         <!-- Kalender: feste Position direkt unter Heute/Aufgaben, damit die wachsende
              Lerngruppen-Liste darunter ihn nicht nach unten verdrängt. -->
         <Border Grid.Column="{Binding CalendarCard.Column}" Grid.Row="{Binding CalendarCard.Row}"
-                IsVisible="{Binding CalendarCard.IsVisible}" Margin="0,0,8,8"
+                IsVisible="{Binding CalendarCard.EffectiveIsVisible}" Margin="0,0,8,8"
                 Background="{DynamicResource SystemControlBackgroundAltHighBrush}"
                 CornerRadius="8" Padding="16">
           <StackPanel Spacing="8">
@@ -317,7 +351,7 @@
 
         <!-- Offene Entschuldigungen: neben dem Kalender, ebenfalls feste Position -->
         <Border Grid.Column="{Binding ExcusesCard.Column}" Grid.Row="{Binding ExcusesCard.Row}"
-                IsVisible="{Binding ExcusesCard.IsVisible}" Margin="8,0,0,8" VerticalAlignment="Top"
+                IsVisible="{Binding ExcusesCard.EffectiveIsVisible}" Margin="8,0,0,8" VerticalAlignment="Top"
                 Background="{DynamicResource SystemControlBackgroundAltHighBrush}"
                 CornerRadius="8" Padding="16">
           <StackPanel>
@@ -351,7 +385,7 @@
 
         <!-- Fehlzeiten-Warnung (5.2.3) -->
         <Border Grid.Column="{Binding AttendanceCard.Column}" Grid.Row="{Binding AttendanceCard.Row}"
-                IsVisible="{Binding AttendanceCard.IsVisible}" Margin="0,0,8,8" VerticalAlignment="Top"
+                IsVisible="{Binding AttendanceCard.EffectiveIsVisible}" Margin="0,0,8,8" VerticalAlignment="Top"
                 Background="{DynamicResource SystemControlBackgroundAltHighBrush}"
                 CornerRadius="8" Padding="16">
           <StackPanel>
@@ -381,7 +415,7 @@
 
         <!-- Förderplan-Wiedervorlage (5.3.2) -->
         <Border Grid.Column="{Binding SupportCard.Column}" Grid.Row="{Binding SupportCard.Row}"
-                IsVisible="{Binding SupportCard.IsVisible}" Margin="8,0,0,8" VerticalAlignment="Top"
+                IsVisible="{Binding SupportCard.EffectiveIsVisible}" Margin="8,0,0,8" VerticalAlignment="Top"
                 Background="{DynamicResource SystemControlBackgroundAltHighBrush}"
                 CornerRadius="8" Padding="16">
           <StackPanel>
@@ -412,7 +446,7 @@
 
         <!-- Anstehende Termine (9.3) -->
         <Border Grid.Column="{Binding UpcomingCard.Column}" Grid.Row="{Binding UpcomingCard.Row}"
-                IsVisible="{Binding UpcomingCard.IsVisible}" Margin="0,0,8,8" VerticalAlignment="Top"
+                IsVisible="{Binding UpcomingCard.EffectiveIsVisible}" Margin="0,0,8,8" VerticalAlignment="Top"
                 Background="{DynamicResource SystemControlBackgroundAltHighBrush}"
                 CornerRadius="8" Padding="16">
           <StackPanel>
@@ -449,7 +483,7 @@
 
         <!-- Offene Korrekturen (9.4) -->
         <Border Grid.Column="{Binding CorrectionsCard.Column}" Grid.Row="{Binding CorrectionsCard.Row}"
-                IsVisible="{Binding CorrectionsCard.IsVisible}" Margin="8,0,0,8" VerticalAlignment="Top"
+                IsVisible="{Binding CorrectionsCard.EffectiveIsVisible}" Margin="8,0,0,8" VerticalAlignment="Top"
                 Background="{DynamicResource SystemControlBackgroundAltHighBrush}"
                 CornerRadius="8" Padding="16">
           <StackPanel>
@@ -482,7 +516,7 @@
 
         <!-- Ungeplante Stunden -->
         <Border Grid.Column="{Binding UnplannedCard.Column}" Grid.Row="{Binding UnplannedCard.Row}"
-                IsVisible="{Binding UnplannedCard.IsVisible}" Margin="0,0,8,8" VerticalAlignment="Top"
+                IsVisible="{Binding UnplannedCard.EffectiveIsVisible}" Margin="0,0,8,8" VerticalAlignment="Top"
                 Background="{DynamicResource SystemControlBackgroundAltHighBrush}"
                 CornerRadius="8" Padding="16">
           <StackPanel>
@@ -512,7 +546,7 @@
 
         <!-- Auffälligkeiten (9.5) -->
         <Border Grid.Column="{Binding AlertsCard.Column}" Grid.Row="{Binding AlertsCard.Row}"
-                IsVisible="{Binding AlertsCard.IsVisible}" Margin="0,0,8,8" VerticalAlignment="Top"
+                IsVisible="{Binding AlertsCard.EffectiveIsVisible}" Margin="0,0,8,8" VerticalAlignment="Top"
                 Background="{DynamicResource SystemControlBackgroundAltHighBrush}"
                 CornerRadius="8" Padding="16">
           <StackPanel>
@@ -546,7 +580,7 @@
 
         <!-- Meine Lerngruppen -->
         <Border Grid.Column="{Binding GroupsCard.Column}" Grid.Row="{Binding GroupsCard.Row}"
-                IsVisible="{Binding GroupsCard.IsVisible}"
+                IsVisible="{Binding GroupsCard.EffectiveIsVisible}"
                 Background="{DynamicResource SystemControlBackgroundAltHighBrush}"
                 CornerRadius="8" Padding="16">
           <StackPanel>

LehrerApp.Desktop/Views/Dashboard/DashboardView.axaml.cs

@@ -1,7 +1,14 @@
 using Avalonia.Controls;
+using Avalonia.Interactivity;
+using LehrerApp.Core.Interfaces;
 using LehrerApp.Core.Models;
+using LehrerApp.Core.Services;
+using LehrerApp.Desktop.Services;
 using LehrerApp.Desktop.ViewModels;
+using LehrerApp.Desktop.ViewModels.Students;
+using LehrerApp.Desktop.Views.Students;
 using LehrerApp.Desktop.Views.Workload;
+using Microsoft.Extensions.DependencyInjection;
 
 namespace LehrerApp.Desktop.Views.Dashboard;
 
@@ -22,4 +29,17 @@ public partial class DashboardView : UserControl
         if (owner is null) return null;
         return await WorkTaskDialogHelper.ShowDialog(owner, startAsReminder: startAsReminder);
     }
+
+    private async void OnCompareWebUntisDocumentationClick(object? sender, RoutedEventArgs e)
+    {
+        var owner = TopLevel.GetTopLevel(this) as Window;
+        if (owner is null) return;
+        var dialogVm = new WebUntisDocumentationComparisonViewModel(
+            App.Services.GetRequiredService<WebUntisIntegrationService>(),
+            App.Services.GetRequiredService<IStudentRepository>(),
+            App.Services.GetRequiredService<IGroupRepository>(),
+            App.Services.GetRequiredService<IDocumentationRepository>(),
+            App.Services.GetRequiredService<SchoolYearService>());
+        await new WebUntisDocumentationComparisonDialog { DataContext = dialogVm }.ShowDialog(owner);
+    }
 }

LehrerApp.Desktop/Views/Exams/ExamsOverviewView.axaml

@@ -0,0 +1,222 @@
+<UserControl xmlns="https://github.com/avaloniaui"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:vm="clr-namespace:LehrerApp.Desktop.ViewModels.Exams"
+             xmlns:vmg="clr-namespace:LehrerApp.Desktop.ViewModels.Groups"
+             xmlns:shared="clr-namespace:LehrerApp.Desktop.Views.Shared"
+             x:Class="LehrerApp.Desktop.Views.Exams.ExamsOverviewView"
+             x:DataType="vm:ExamsOverviewViewModel">
+
+  <!-- Statusfarben kommen wie im Klassenlehrer-Bereich aus Styles/SemanticBrushes.axaml (siehe
+       ClassTeacherOverviewView) — Basis ist hier aber "neutral" statt "ok", weil geplante bzw.
+       hängengebliebene Klausuren (ExamPriorityService.CorrectionStuck) hier den Normalfall
+       bilden, nicht ein positives Ergebnis. -->
+  <UserControl.Styles>
+    <Style Selector="Border.examStatusBar">
+      <Setter Property="Background" Value="{DynamicResource AppListRowBorderBrush}"/>
+    </Style>
+    <Style Selector="Border.examStatusBar.ok">
+      <Setter Property="Background" Value="{DynamicResource AppStatusOkBrush}"/>
+    </Style>
+    <Style Selector="Border.examStatusBar.info">
+      <Setter Property="Background" Value="{DynamicResource AppStatusInfoBrush}"/>
+    </Style>
+    <Style Selector="Border.examStatusBar.warning">
+      <Setter Property="Background" Value="{DynamicResource AppStatusWarningBrush}"/>
+    </Style>
+    <Style Selector="Border.examStatusBar.danger">
+      <Setter Property="Background" Value="{DynamicResource AppStatusDangerBrush}"/>
+    </Style>
+    <Style Selector="Border.examStatusPill">
+      <Setter Property="Background" Value="{DynamicResource AppChipBackgroundBrush}"/>
+      <Setter Property="CornerRadius" Value="4"/>
+      <Setter Property="Padding" Value="8,2"/>
+    </Style>
+    <Style Selector="Border.examStatusPill TextBlock">
+      <Setter Property="FontSize" Value="12"/>
+    </Style>
+    <Style Selector="Border.examStatusPill.ok">
+      <Setter Property="Background" Value="{DynamicResource AppStatusOkBrush}"/>
+    </Style>
+    <Style Selector="Border.examStatusPill.ok TextBlock">
+      <Setter Property="Foreground" Value="White"/>
+    </Style>
+    <Style Selector="Border.examStatusPill.info">
+      <Setter Property="Background" Value="{DynamicResource AppStatusInfoBrush}"/>
+    </Style>
+    <Style Selector="Border.examStatusPill.info TextBlock">
+      <Setter Property="Foreground" Value="White"/>
+    </Style>
+    <Style Selector="Border.examStatusPill.warning">
+      <Setter Property="Background" Value="{DynamicResource AppStatusWarningBrush}"/>
+    </Style>
+    <Style Selector="Border.examStatusPill.warning TextBlock">
+      <Setter Property="Foreground" Value="White"/>
+    </Style>
+    <Style Selector="Border.examStatusPill.danger">
+      <Setter Property="Background" Value="{DynamicResource AppStatusDangerBrush}"/>
+    </Style>
+    <Style Selector="Border.examStatusPill.danger TextBlock">
+      <Setter Property="Foreground" Value="White"/>
+    </Style>
+    <Style Selector="Button.examRow">
+      <Setter Property="HorizontalAlignment" Value="Stretch"/>
+      <Setter Property="HorizontalContentAlignment" Value="Stretch"/>
+      <Setter Property="Background" Value="{DynamicResource AppListRowBackgroundBrush}"/>
+      <Setter Property="BorderBrush" Value="{DynamicResource AppListRowBorderBrush}"/>
+      <Setter Property="BorderThickness" Value="1,0,1,1"/>
+      <Setter Property="Padding" Value="0"/>
+      <Setter Property="CornerRadius" Value="0"/>
+    </Style>
+    <Style Selector="Button.examRow:pointerover /template/ ContentPresenter">
+      <Setter Property="Background" Value="{DynamicResource AppListRowHoverBrush}"/>
+    </Style>
+    <Style Selector="Button.siblingPill">
+      <Setter Property="Padding" Value="10,4"/>
+      <Setter Property="FontSize" Value="12"/>
+      <Setter Property="CornerRadius" Value="12"/>
+    </Style>
+  </UserControl.Styles>
+
+  <Grid RowDefinitions="Auto,Auto,*">
+    <Border Grid.Row="0" Padding="20,16"
+            BorderBrush="{DynamicResource SystemControlForegroundBaseLowBrush}"
+            BorderThickness="0,0,0,1">
+      <Grid ColumnDefinitions="*,Auto">
+        <shared:PageHeader Grid.Column="0" Title="Klausuren"
+                            Subtitle="Alle Klausuren des Schuljahres, nach Dringlichkeit sortiert"/>
+        <Button Grid.Column="1" Content="↻  Aktualisieren" Command="{Binding LoadCommand}"
+                VerticalAlignment="Center"/>
+      </Grid>
+    </Border>
+
+    <!-- Detailbereich zur ausgewählten Klausur ─────────────────────────────────── -->
+    <Border Grid.Row="1" Margin="20,16,20,10" Padding="18"
+            Background="{DynamicResource AppCardBackgroundBrush}"
+            BorderBrush="{DynamicResource AppCardBorderBrush}" BorderThickness="1" CornerRadius="10"
+            IsVisible="{Binding HasSelection}">
+      <StackPanel Spacing="12">
+        <Grid ColumnDefinitions="*,Auto">
+          <StackPanel Grid.Column="0" Spacing="2">
+            <TextBlock Text="{Binding SelectedRow.Title}" FontSize="16" FontWeight="SemiBold"/>
+            <TextBlock FontSize="13" Opacity="0.6">
+              <Run Text="{Binding SelectedRow.GroupLabel}"/>
+              <Run Text=" · "/>
+              <Run Text="{Binding SelectedRow.SubLabel}"/>
+            </TextBlock>
+          </StackPanel>
+          <Border Grid.Column="1" Classes="examStatusPill" VerticalAlignment="Top"
+                  Classes.ok="{Binding SelectedRow.IsOk}" Classes.info="{Binding SelectedRow.IsInfo}"
+                  Classes.warning="{Binding SelectedRow.IsWarning}" Classes.danger="{Binding SelectedRow.IsDanger}">
+            <TextBlock Text="{Binding SelectedRow.StatusLabel}"/>
+          </Border>
+        </Grid>
+
+        <!-- Parallelkurs-Umschalter -->
+        <ItemsControl ItemsSource="{Binding Siblings}" IsVisible="{Binding SelectedRow.HasSibling}">
+          <ItemsControl.ItemsPanel>
+            <ItemsPanelTemplate>
+              <StackPanel Orientation="Horizontal" Spacing="8"/>
+            </ItemsPanelTemplate>
+          </ItemsControl.ItemsPanel>
+          <ItemsControl.ItemTemplate>
+            <DataTemplate x:DataType="vm:ExamListRowViewModel">
+              <Button Classes="siblingPill"
+                      Command="{Binding $parent[ItemsControl].((vm:ExamsOverviewViewModel)DataContext).SelectExamCommand}"
+                      CommandParameter="{Binding}">
+                <TextBlock>
+                  <Run Text="{Binding GroupLabel}"/>
+                  <Run Text=" · "/>
+                  <Run Text="{Binding Evaluated}"/>
+                  <Run Text="/"/>
+                  <Run Text="{Binding Expected}"/>
+                </TextBlock>
+              </Button>
+            </DataTemplate>
+          </ItemsControl.ItemTemplate>
+        </ItemsControl>
+
+        <!-- Korrekturfortschritt -->
+        <StackPanel Spacing="6" IsVisible="{Binding ShowCorrectionProgress}">
+          <TextBlock Text="{Binding ProgressLabel}" FontSize="13"/>
+          <Border Width="240" Height="6" CornerRadius="3" HorizontalAlignment="Left"
+                  Background="{DynamicResource AppTrackBackgroundBrush}">
+            <Border Width="{Binding ProgressBarWidth}" Height="6" CornerRadius="3"
+                    HorizontalAlignment="Left" Background="{DynamicResource AppStatusWarningBrush}"/>
+          </Border>
+        </StackPanel>
+
+        <!-- Notenspiegel -->
+        <StackPanel Spacing="6" IsVisible="{Binding ShowGradeSummary}">
+          <TextBlock Text="{Binding AverageLabel}" FontSize="14" FontWeight="SemiBold"/>
+          <ItemsControl ItemsSource="{Binding DetailGradeDistribution}">
+            <ItemsControl.ItemTemplate>
+              <DataTemplate x:DataType="vmg:GradeBarItem">
+                <Grid ColumnDefinitions="30,*,60" Margin="0,1">
+                  <TextBlock Grid.Column="0" Text="{Binding Grade}" FontSize="12" VerticalAlignment="Center"/>
+                  <Border Grid.Column="1" Height="14" Width="{Binding BarWidth}" HorizontalAlignment="Left"
+                          Background="{DynamicResource AppAccentTextBrush}" CornerRadius="3"/>
+                  <TextBlock Grid.Column="2" Text="{Binding CountDisplay}" FontSize="11" Opacity="0.6"
+                             VerticalAlignment="Center"/>
+                </Grid>
+              </DataTemplate>
+            </ItemsControl.ItemTemplate>
+          </ItemsControl>
+        </StackPanel>
+
+        <!-- Genehmigung / Ankündigung -->
+        <StackPanel Orientation="Horizontal" Spacing="10">
+          <Button Content="{Binding ApprovalLabel}" Command="{Binding ToggleApprovalCommand}" FontSize="12"/>
+          <Button Content="{Binding AnnouncementLabel}" Command="{Binding ToggleAnnouncementCommand}" FontSize="12"/>
+        </StackPanel>
+
+        <StackPanel Orientation="Horizontal" Spacing="8">
+          <Button Content="Punkte eingeben" Command="{Binding GradeSelectedCommand}"
+                  IsVisible="{Binding ShowCorrectionProgress}"/>
+          <Button Content="Auswertung" Command="{Binding EvaluateSelectedCommand}"
+                  IsVisible="{Binding ShowGradeSummary}"/>
+          <Button Content="Zum Kurs →" Command="{Binding GoToGroupCommand}" HorizontalAlignment="Right"/>
+        </StackPanel>
+      </StackPanel>
+    </Border>
+
+    <!-- Liste aller Klausuren, nach Priorität sortiert (nicht nach Datum) ─────────── -->
+    <ScrollViewer Grid.Row="2" Margin="20,0,20,16">
+      <StackPanel>
+        <TextBlock Text="{Binding EmptyHint}" Classes="emptyhint" Margin="0,20,0,0"
+                    IsVisible="{Binding EmptyHint, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"/>
+        <ItemsControl ItemsSource="{Binding Rows}">
+          <ItemsControl.ItemTemplate>
+            <DataTemplate x:DataType="vm:ExamListRowViewModel">
+              <Button Classes="examRow"
+                      Command="{Binding $parent[ItemsControl].((vm:ExamsOverviewViewModel)DataContext).SelectExamCommand}"
+                      CommandParameter="{Binding}">
+                <Grid ColumnDefinitions="4,*,Auto,Auto" MinHeight="52">
+                  <Border Grid.Column="0" Classes="examStatusBar" Classes.ok="{Binding IsOk}"
+                          Classes.info="{Binding IsInfo}" Classes.warning="{Binding IsWarning}"
+                          Classes.danger="{Binding IsDanger}"/>
+                  <StackPanel Grid.Column="1" VerticalAlignment="Center" Margin="12,6" Spacing="2">
+                    <StackPanel Orientation="Horizontal" Spacing="6">
+                      <TextBlock Text="{Binding Title}" FontSize="14" FontWeight="Medium"/>
+                      <TextBlock Text="🔗" FontSize="11" Opacity="0.5" IsVisible="{Binding HasSibling}"
+                                 ToolTip.Tip="Parallelkurs vorhanden"/>
+                    </StackPanel>
+                    <TextBlock FontSize="12" Opacity="0.6">
+                      <Run Text="{Binding GroupLabel}"/>
+                      <Run Text=" · "/>
+                      <Run Text="{Binding SubLabel}"/>
+                    </TextBlock>
+                  </StackPanel>
+                  <Border Grid.Column="3" Classes="examStatusPill" VerticalAlignment="Center" Margin="0,0,12,0"
+                          Classes.ok="{Binding IsOk}" Classes.info="{Binding IsInfo}"
+                          Classes.warning="{Binding IsWarning}" Classes.danger="{Binding IsDanger}">
+                    <TextBlock Text="{Binding StatusLabel}"/>
+                  </Border>
+                </Grid>
+              </Button>
+            </DataTemplate>
+          </ItemsControl.ItemTemplate>
+        </ItemsControl>
+      </StackPanel>
+    </ScrollViewer>
+  </Grid>
+</UserControl>

LehrerApp.Desktop/Views/Exams/ExamsOverviewView.axaml.cs

@@ -0,0 +1,63 @@
+using Avalonia.Controls;
+using LehrerApp.Core.Interfaces;
+using LehrerApp.Core.Models;
+using LehrerApp.Core.Services;
+using LehrerApp.Desktop.ViewModels;
+using LehrerApp.Desktop.ViewModels.Exams;
+using LehrerApp.Desktop.ViewModels.Groups;
+using LehrerApp.Desktop.Views.Groups;
+using Microsoft.Extensions.DependencyInjection;
+
+namespace LehrerApp.Desktop.Views.Exams;
+
+public partial class ExamsOverviewView : UserControl
+{
+    private const int GroupDetailKlausurenTabIndex = 4;
+
+    public ExamsOverviewView() => InitializeComponent();
+
+    protected override void OnDataContextChanged(EventArgs e)
+    {
+        base.OnDataContextChanged(e);
+        if (DataContext is ExamsOverviewViewModel vm)
+        {
+            vm.OnGradeExam = ShowGradeExamDialog;
+            vm.OnEvaluateExam = ShowEvaluateExamDialog;
+            vm.OnNavigateToGroup = groupId => App.Services.GetRequiredService<MainWindowViewModel>()
+                .NavigateToGroupDetail(groupId, GroupDetailKlausurenTabIndex);
+        }
+    }
+
+    private async Task ShowGradeExamDialog(Exam exam)
+    {
+        var group = App.Services.GetRequiredService<IGroupRepository>().GetById(exam.GroupId);
+        if (group is null) return;
+
+        var dialogVm = new ExamGradingDialogViewModel(
+            App.Services.GetRequiredService<IExamResultRepository>(),
+            App.Services.GetRequiredService<IStudentRepository>(),
+            App.Services.GetRequiredService<IGroupMembershipRepository>(),
+            App.Services.GetRequiredService<GradingService>(),
+            exam, group.Id);
+
+        var dialog = new ExamGradingDialog { DataContext = dialogVm };
+        var owner = TopLevel.GetTopLevel(this) as Window;
+        if (owner is not null) await dialog.ShowDialog(owner);
+    }
+
+    private async Task ShowEvaluateExamDialog(Exam exam)
+    {
+        var group = App.Services.GetRequiredService<IGroupRepository>().GetById(exam.GroupId);
+        if (group is null) return;
+
+        var dialogVm = new ExamEvaluationDialogViewModel(
+            App.Services.GetRequiredService<IExamRepository>(),
+            App.Services.GetRequiredService<IExamResultRepository>(),
+            App.Services.GetRequiredService<GradingService>(),
+            exam, group.GradingSystem);
+
+        var dialog = new ExamEvaluationDialog { DataContext = dialogVm };
+        var owner = TopLevel.GetTopLevel(this) as Window;
+        if (owner is not null) await dialog.ShowDialog(owner);
+    }
+}

LehrerApp.Desktop/Views/Groups/AddGroupDialog.axaml

@@ -77,6 +77,13 @@
       <CheckBox Content="Benötigt Unterrichtsplanung" IsChecked="{Binding RequiresLessonPlanning}"
                 ToolTip.Tip="Deaktivieren für Gruppen ohne inhaltlichen Verlaufsplan (z.B. Klassenrat, Willkommenskreis) - blendet für diese Gruppe die Dashboard-Erinnerung &quot;Ungeplante Stunden&quot; aus."/>
 
+      <StackPanel Spacing="4">
+        <TextBlock Text="WebUntis-Unterrichtsnummer (optional)" FontSize="12" Opacity="0.7"/>
+        <NumericUpDown Value="{Binding WebUntisLessonId}" Minimum="1" FormatString="0"
+                       HorizontalAlignment="Stretch"
+                       ToolTip.Tip="lsid aus WebUntis (Unterricht -&gt; Mein Unterricht -&gt; Berichte-Symbol der Zeile). Wird von WebUntis pro Schuljahr neu vergeben und muss deshalb jedes Schuljahr aktualisiert werden."/>
+      </StackPanel>
+
     </StackPanel>
 
     <Grid Grid.Row="1" ColumnDefinitions="*,8,*" Margin="0,20,0,0">

LehrerApp.Desktop/Views/Groups/ExamGradingDialog.axaml

@@ -15,6 +15,9 @@
               IsVisible="{Binding NiveauLabel, Converter={x:Static StringConverters.IsNotNullOrEmpty}}">
         <TextBlock Text="{Binding NiveauLabel}" FontSize="12" Foreground="White"/>
       </Border>
+      <Button Content="Rest als abwesend markieren" Command="{Binding MarkRemainingAbsentCommand}"
+              Margin="20,0,0,0" VerticalAlignment="Center"
+              ToolTip.Tip="Setzt bei allen noch leeren Zeilen 'Abwesend' — für Schüler, die nicht nachschreiben."/>
     </StackPanel>
 
     <DataGrid Grid.Row="1" Name="ResultGrid"

LehrerApp.Desktop/Views/Groups/GroupDetailView.axaml

@@ -25,6 +25,9 @@
           <Button Content="＋ Schüler" Command="{Binding AddStudentCommand}" IsEnabled="{Binding IsEditable}"/>
           <Button Content="⇩ Teilnehmer importieren…" Click="OnImportParticipantsClick"
                   IsEnabled="{Binding IsEditable}"/>
+          <Button Content="↻ Aus WebUntis…" Click="OnImportParticipantsFromWebUntisClick"
+                  IsEnabled="{Binding IsEditable}"/>
+          <Button Content="Fehlzeiten je Unterricht…" Click="OnCompareWebUntisLessonAbsencesClick"/>
           <Button Content="{Binding SelectedStudent.WithdrawActionLabel}"
                   Command="{Binding WithdrawStudentCommand}"
                   IsVisible="{Binding SelectedStudent, Converter={x:Static ObjectConverters.IsNotNull}}"/>

LehrerApp.Desktop/Views/Groups/GroupDetailView.axaml.cs

@@ -13,6 +13,8 @@ using LehrerApp.Desktop.Views.Shared;
 using LehrerApp.Desktop.Views.Students;
 using LehrerApp.Desktop.Views.Workload;
 using Microsoft.Extensions.DependencyInjection;
+using System.Globalization;
+using System.Text;
 
 namespace LehrerApp.Desktop.Views.Groups;
 
@@ -113,18 +115,7 @@ public partial class GroupDetailView : UserControl
                 throw new InvalidDataException("Die Importdatei ist größer als 20 MB.");
 
             var importFile = new ImportFile(files[0].Name, buffer.ToArray());
-            var preview = await Task.Run(async () =>
+            await ShowStudentImportPreview(owner, vm, importFile, files[0].Name);
-                await service.AnalyzeAsync(importFile, vm.Group.Id).ConfigureAwait(false));
-            var dialogVm = new StudentImportDialogViewModel(service, preview, files[0].Name);
-            var dialog = new StudentImportDialog { DataContext = dialogVm };
-            if (!await dialog.ShowDialog<bool>(owner)) return;
-
-            vm.LoadStudents();
-            vm.ParticipationTab.RefreshCurrentGrid();
-            var result = dialogVm.Result!;
-            App.Services.GetRequiredService<NotificationService>().ShowSuccess(
-                $"Teilnehmerimport abgeschlossen: {result.CreatedStudents} neu, "
-                + $"{result.UpdatedStudents} ergänzt, {result.CreatedMemberships} zugeordnet.");
         }
         catch (Exception ex) when (ex is ImportFormatException
                                    or InvalidDataException
@@ -135,6 +126,96 @@ public partial class GroupDetailView : UserControl
         }
     }
 
+    private async void OnImportParticipantsFromWebUntisClick(object? sender, RoutedEventArgs e)
+    {
+        var owner = TopLevel.GetTopLevel(this) as Window;
+        if (owner is null || DataContext is not GroupDetailViewModel vm || vm.Group is null) return;
+        try
+        {
+            var untis = App.Services.GetRequiredService<WebUntisIntegrationService>();
+            var selectionVm = new WebUntisClassSelectionViewModel(untis);
+            var selection = new WebUntisClassSelectionDialog { DataContext = selectionVm };
+            await selectionVm.InitializeAsync();
+            if (!await selection.ShowDialog<bool>(owner) || selectionVm.SelectedClass is null) return;
+
+            var report = await untis.GetStudentsAsync(selectionVm.SelectedClass.Name);
+            var importFile = BuildWebUntisStudentImport(report);
+            await ShowStudentImportPreview(owner, vm, importFile,
+                $"WebUntis · {selectionVm.SelectedClass.Name}");
+        }
+        catch (WebUntisIntegrationException ex)
+        {
+            App.Services.GetRequiredService<NotificationService>().ShowError(ex.Message);
+        }
+        catch (Exception ex) when (ex is ImportFormatException or InvalidDataException)
+        {
+            App.Services.GetRequiredService<NotificationService>().ShowError(ex.Message);
+        }
+    }
+
+    private async void OnCompareWebUntisLessonAbsencesClick(object? sender, RoutedEventArgs e)
+    {
+        var owner = TopLevel.GetTopLevel(this) as Window;
+        if (owner is null || DataContext is not GroupDetailViewModel vm || vm.Group is null) return;
+        var dialogVm = new WebUntisLessonAbsenceComparisonViewModel(vm.Group,
+            App.Services.GetRequiredService<WebUntisIntegrationService>(),
+            App.Services.GetRequiredService<IStudentRepository>(),
+            App.Services.GetRequiredService<IParticipationSessionRepository>(),
+            App.Services.GetRequiredService<IParticipationRepository>());
+        await new WebUntisLessonAbsenceComparisonDialog { DataContext = dialogVm }.ShowDialog(owner);
+        vm.ParticipationTab.RefreshCurrentGrid();
+    }
+
+    private static ImportFile BuildWebUntisStudentImport(UntisStudentReportDto report)
+    {
+        var builder = new StringBuilder();
+        builder.AppendLine("longName\tforeName\tgender\tbirthDate\tklasse.name\texternKey\taddress.email\taddress.mobile\taddress.phone\taddress.city\taddress.postCode\taddress.street");
+        foreach (var student in report.Students)
+        {
+            var values = new[]
+            {
+                student.LongName ?? student.Name, student.ForeName, student.Gender,
+                FormatBirthDate(student), student.ClassName,
+                student.ExternKey.ToString(), student.Address.Email, student.Address.Mobile,
+                student.Address.Phone, student.Address.City, student.Address.PostCode, student.Address.Street,
+            };
+            builder.AppendLine(string.Join('\t', values.Select(SafeTsv)));
+        }
+        return new ImportFile("webuntis-students.csv", Encoding.UTF8.GetBytes(builder.ToString()));
+    }
+
+    private static string? FormatBirthDate(UntisStudentDto student)
+    {
+        if (student.BirthDate is not { } normalizedDate) return student.BirthDateRaw;
+
+        var value = normalizedDate.ToString("D8", CultureInfo.InvariantCulture);
+        return DateOnly.TryParseExact(value, "yyyyMMdd", CultureInfo.InvariantCulture,
+            DateTimeStyles.None, out var date)
+            ? date.ToString("dd.MM.yyyy", CultureInfo.InvariantCulture)
+            : student.BirthDateRaw;
+    }
+
+    private static string SafeTsv(string? value) => (value ?? "").Replace('\t', ' ')
+        .Replace('\r', ' ').Replace('\n', ' ');
+
+    private static async Task ShowStudentImportPreview(Window owner, GroupDetailViewModel vm,
+        ImportFile importFile, string sourceName)
+    {
+        var service = App.Services.GetRequiredService<StudentImportService>();
+        var preview = await Task.Run(async () =>
+            await service.AnalyzeAsync(importFile, vm.Group!.Id).ConfigureAwait(false));
+        var dialogVm = new StudentImportDialogViewModel(service, preview, sourceName);
+        var dialog = new StudentImportDialog { DataContext = dialogVm };
+        if (!await dialog.ShowDialog<bool>(owner)) return;
+
+        vm.LoadStudents();
+        vm.ParticipationTab.RefreshCurrentGrid();
+        var result = dialogVm.Result!;
+        App.Services.GetRequiredService<NotificationService>().ShowSuccess(
+            $"Teilnehmerimport abgeschlossen: {result.CreatedStudents} neu, "
+            + $"{result.UpdatedStudents} ergänzt, {result.CreatedMemberships} zugeordnet.");
+    }
+
     private async Task<bool> ShowWithdrawStudentDialog(StudentSummary student)
     {
         if (DataContext is not GroupDetailViewModel vm || vm.Group is null) return false;

LehrerApp.Desktop/Views/Groups/GroupListView.axaml

@@ -5,13 +5,6 @@
              x:Class="LehrerApp.Desktop.Views.Groups.GroupListView"
              x:DataType="vm:GroupListViewModel">
 
-  <UserControl.Styles>
-    <Style Selector="TextBlock.overdue">
-      <Setter Property="Foreground" Value="Red"/>
-      <Setter Property="FontWeight" Value="SemiBold"/>
-    </Style>
-  </UserControl.Styles>
-
   <Grid RowDefinitions="Auto,*">
 
     <!-- Kopfzeile mit Schuljahr-Wähler und Neu-Button -->
@@ -28,180 +21,85 @@
       </Grid>
     </Border>
 
-    <!-- Master-Detail: Liste links, Übersicht rechts -->
+    <!-- Eine Navigationsebene: Karten öffnen direkt das Gruppendetail. Die Verwaltung sitzt
-    <Grid Grid.Row="1" ColumnDefinitions="260,*">
+         am jeweiligen Eintrag und benötigt keine vorgeschaltete Bereichsauswahl mehr. -->
+    <Grid Grid.Row="1" RowDefinitions="Auto,*">
+      <Grid Grid.Row="0" ColumnDefinitions="*,Auto" Margin="24,18,24,8">
+        <TextBox Grid.Column="0" Text="{Binding SearchText}"
+                 PlaceholderText="Name oder Fach suchen …" MaxWidth="560"
+                 HorizontalAlignment="Stretch"/>
+        <ToggleSwitch Grid.Column="1" Content="Archiv anzeigen" IsChecked="{Binding ShowArchived}"
+                      Margin="20,0,0,0" VerticalAlignment="Center"/>
+      </Grid>
 
-      <!-- Linke Spalte: Sucheingabe + Listenansicht -->
+      <StackPanel Grid.Row="1" HorizontalAlignment="Center" VerticalAlignment="Center" Spacing="10"
-      <Border Grid.Column="0"
+                  IsVisible="{Binding HasNoGroups}">
-              BorderBrush="{DynamicResource SystemControlForegroundBaseLowBrush}"
+        <TextBlock Text="{Binding EmptyListMessage}" FontSize="15" Opacity="0.55"
-              BorderThickness="0,0,1,0">
+                   TextWrapping="Wrap" TextAlignment="Center"/>
-        <DockPanel>
+        <Button Content="＋ Erste Lerngruppe anlegen" Command="{Binding AddGroupCommand}"
-          <StackPanel DockPanel.Dock="Top" Margin="12,8" Spacing="8">
+                IsVisible="{Binding !ShowArchived}" HorizontalAlignment="Center"/>
-            <TextBox Text="{Binding SearchText}" PlaceholderText="Suchen…"/>
-            <ToggleSwitch Content="Archiv anzeigen" IsChecked="{Binding ShowArchived}"/>
-          </StackPanel>
-          <TextBlock Text="{Binding EmptyListMessage}" TextWrapping="Wrap"
-                     Margin="16,12" FontSize="12" Opacity="0.45"
-                     IsVisible="{Binding HasNoGroups}"/>
-          <ListBox ItemsSource="{Binding Groups}"
-                   SelectedItem="{Binding SelectedGroup}">
-            <ListBox.ItemTemplate>
-              <DataTemplate DataType="vm:GroupListItem">
-                <Grid ColumnDefinitions="4,*" Margin="2,4">
-                  <Border Grid.Column="0" Width="4" CornerRadius="2"
-                          Background="{DynamicResource SystemAccentColor}"
-                          Margin="0,0,10,0"/>
-                  <StackPanel Grid.Column="1">
-                    <Grid ColumnDefinitions="*,Auto">
-                      <TextBlock Grid.Column="0" Text="{Binding Name}"
-                                 FontWeight="SemiBold" FontSize="13"/>
-                      <TextBlock Grid.Column="1" Text="{Binding TypeLabel}"
-                                 FontSize="11" Opacity="0.5"/>
-                    </Grid>
-                    <TextBlock Text="{Binding Subject}" FontSize="12" Opacity="0.65"
-                               IsVisible="{Binding Subject, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"/>
-                    <TextBlock Text="{Binding GradingLabel}" FontSize="11" Opacity="0.4"/>
-                  </StackPanel>
-                </Grid>
-              </DataTemplate>
-            </ListBox.ItemTemplate>
-          </ListBox>
-        </DockPanel>
-      </Border>
-
-      <!-- Rechte Spalte: Platzhalter wenn keine Auswahl -->
-      <StackPanel Grid.Column="1" HorizontalAlignment="Center"
-                  VerticalAlignment="Center" Spacing="8"
-                  IsVisible="{Binding SelectedGroup, Converter={x:Static ObjectConverters.IsNull}}">
-        <TextBlock Text="Gruppe auswählen" FontSize="16" Opacity="0.4"
-                   HorizontalAlignment="Center"/>
-        <TextBlock Text="oder ＋ Neue Gruppe anlegen" FontSize="12" Opacity="0.3"
-                   HorizontalAlignment="Center"/>
       </StackPanel>
 
-      <!-- Rechte Spalte: Gruppen-Übersicht wenn ausgewählt -->
+      <ScrollViewer Grid.Row="1" IsVisible="{Binding !HasNoGroups}"
-      <ScrollViewer Grid.Column="1"
+                    HorizontalScrollBarVisibility="Disabled">
-                    IsVisible="{Binding SelectedGroup, Converter={x:Static ObjectConverters.IsNotNull}}">
+        <ItemsControl ItemsSource="{Binding Groups}" Margin="20,12,20,24">
-        <StackPanel Margin="28,24" Spacing="20">
+          <ItemsControl.ItemsPanel>
-
+            <ItemsPanelTemplate>
-          <!-- Gruppenname und Kurzinfos -->
+              <WrapPanel Orientation="Horizontal"/>
-          <Grid ColumnDefinitions="*,Auto">
+            </ItemsPanelTemplate>
-            <StackPanel Grid.Column="0" Spacing="4">
+          </ItemsControl.ItemsPanel>
-              <TextBlock Text="{Binding SelectedGroupDisplayName}"
+          <ItemsControl.ItemTemplate>
-                         FontSize="24" FontWeight="SemiBold" TextWrapping="Wrap"/>
+            <DataTemplate x:DataType="vm:GroupListItem">
-              <TextBlock Text="{Binding SelectedGroupSubtitle}"
+              <Border Width="330" MinHeight="116" Margin="6" CornerRadius="9"
-                         FontSize="12" Opacity="0.55"/>
+                      Background="{DynamicResource AppCardBackgroundBrush}"
-            </StackPanel>
+                      BorderBrush="{DynamicResource AppCardBorderBrush}" BorderThickness="1">
-            <Button Grid.Column="1" Content="⋯  Verwalten" VerticalAlignment="Top"
+                <Grid ColumnDefinitions="4,*,Auto">
-                    Margin="16,0,0,0">
+                  <Border Grid.Column="0" Background="{DynamicResource SystemAccentColor}"
-              <Button.Flyout>
+                          CornerRadius="9,0,0,9"/>
-                <MenuFlyout>
+                  <Button Grid.Column="1" Background="Transparent" BorderThickness="0"
-                  <MenuItem Header="Details bearbeiten"
+                          Padding="16,14" HorizontalAlignment="Stretch"
-                            Command="{Binding EditGroupCommand}"/>
+                          HorizontalContentAlignment="Stretch" VerticalContentAlignment="Stretch"
-                  <MenuItem Header="Ins nächste Schuljahr übernehmen …"
+                          Command="{Binding OpenCommand}"
-                            Command="{Binding RollOverGroupCommand}"/>
+                          AutomationProperties.Name="{Binding OpenAutomationName}">
-                  <MenuItem Header="{Binding SelectedGroup.ArchiveActionLabel}"
+                    <StackPanel Spacing="6">
-                            Command="{Binding ToggleArchiveCommand}"/>
+                      <TextBlock Text="{Binding Name}" FontSize="17" FontWeight="SemiBold"
-                  <Separator/>
+                                 TextTrimming="CharacterEllipsis"/>
-                  <MenuItem Header="Teilnehmer importieren (bald)" IsEnabled="False"
+                      <TextBlock Text="{Binding Subject}" FontSize="13" Opacity="0.7"
-                            ToolTip.Tip="Import aus dem Teilnehmerexport der Lernplattform folgt."/>
+                                 TextTrimming="CharacterEllipsis"
-                  <Separator/>
+                                 IsVisible="{Binding Subject, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"/>
-                  <MenuItem Header="Lerngruppe löschen"
+                      <StackPanel Orientation="Horizontal" Spacing="7">
-                            Command="{Binding DeleteGroupCommand}"/>
+                        <Border Background="{DynamicResource AppChipBackgroundBrush}" CornerRadius="8" Padding="7,2">
-                </MenuFlyout>
+                          <TextBlock Text="{Binding TypeLabel}" FontSize="10" Opacity="0.75"/>
-              </Button.Flyout>
+                        </Border>
-            </Button>
+                        <TextBlock Text="{Binding GradingLabel}" FontSize="11" Opacity="0.5"
-          </Grid>
+                                   VerticalAlignment="Center"/>
-
+                      </StackPanel>
-          <Separator/>
+                    </StackPanel>
-
+                  </Button>
-          <!-- Schnellüberblick (Nutzer-Feedback) -->
+                  <Button Grid.Column="2" Content="⋯" Width="36" Height="32" Margin="0,10,10,0"
-          <StackPanel Spacing="8" IsVisible="{Binding QuickHasAnything}">
+                          Padding="0" VerticalAlignment="Top"
-            <TextBlock Text="SCHNELLÜBERBLICK" FontSize="10" FontWeight="Bold" Opacity="0.4"/>
+                          ToolTip.Tip="Lerngruppe verwalten"
-            <StackPanel Spacing="1" IsVisible="{Binding QuickHasNextLesson}">
+                          AutomationProperties.Name="{Binding ManageAutomationName}">
-              <TextBlock Text="Nächste Stunde" FontSize="11" Opacity="0.55"/>
+                    <Button.Flyout>
-              <TextBlock Text="{Binding QuickNextLessonLabel}" FontSize="13" TextWrapping="Wrap"/>
+                      <MenuFlyout>
-            </StackPanel>
+                        <MenuItem Header="Details bearbeiten" IsEnabled="{Binding IsActive}"
-            <StackPanel Spacing="1" IsVisible="{Binding QuickHasNextExam}">
+                                  Command="{Binding EditCommand}"/>
-              <TextBlock Text="Nächste Klausur" FontSize="11" Opacity="0.55"/>
+                        <MenuItem Header="Ins nächste Schuljahr übernehmen …"
-              <TextBlock Text="{Binding QuickNextExamLabel}" FontSize="13" TextWrapping="Wrap"/>
+                                  Command="{Binding RollOverCommand}"/>
-            </StackPanel>
+                        <MenuItem Header="{Binding ArchiveActionLabel}"
-            <StackPanel Spacing="4" IsVisible="{Binding QuickHasTasks}">
+                                  Command="{Binding ToggleArchiveCommand}"/>
-              <TextBlock Text="Wichtige Aufgaben" FontSize="11" Opacity="0.55"/>
+                        <Separator/>
-              <ItemsControl ItemsSource="{Binding QuickTasks}">
+                        <MenuItem Header="Lerngruppe löschen" IsEnabled="{Binding IsActive}"
-                <ItemsControl.ItemTemplate>
+                                  Command="{Binding DeleteCommand}"/>
-                  <DataTemplate x:DataType="vm:GroupTaskItem">
+                      </MenuFlyout>
-                    <Grid ColumnDefinitions="4,Auto,*,Auto" Margin="0,2">
+                    </Button.Flyout>
-                      <Border Grid.Column="0" Background="{Binding PriorityColorHex}" CornerRadius="2"
+                  </Button>
-                              Margin="0,0,6,0" IsVisible="{Binding IsHighPriority}"/>
+                </Grid>
-                      <TextBlock Grid.Column="1" Text="🔔" FontSize="11" Margin="0,0,4,0"
+              </Border>
-                                 IsVisible="{Binding IsReminder}" VerticalAlignment="Center"/>
+            </DataTemplate>
-                      <TextBlock Grid.Column="2" Text="{Binding Title}" FontSize="12"
+          </ItemsControl.ItemTemplate>
-                                 TextTrimming="CharacterEllipsis" VerticalAlignment="Center"/>
+        </ItemsControl>
-                      <TextBlock Grid.Column="3" Text="{Binding DueDateDisplay}" FontSize="11"
-                                 VerticalAlignment="Center" Classes.overdue="{Binding IsOverdue}"/>
-                    </Grid>
-                  </DataTemplate>
-                </ItemsControl.ItemTemplate>
-              </ItemsControl>
-            </StackPanel>
-          </StackPanel>
-          <Separator IsVisible="{Binding QuickHasAnything}"/>
-
-          <!-- Bereichs-Navigation -->
-          <TextBlock Text="BEREICHE" FontSize="10" FontWeight="Bold"
-                     Opacity="0.4" Margin="0,0,0,2"/>
-          <StackPanel Spacing="6">
-            <Button Content="📊  Übersicht"
-                    HorizontalAlignment="Stretch" HorizontalContentAlignment="Left"
-                    Padding="12,9"
-                    Command="{Binding NavigateToSectionCommand}"
-                    CommandParameter="0"/>
-            <Button Content="👤  Schülerliste"
-                    HorizontalAlignment="Stretch" HorizontalContentAlignment="Left"
-                    Padding="12,9"
-                    Command="{Binding NavigateToSectionCommand}"
-                    CommandParameter="1"/>
-            <Button Content="🪑  Sitzpläne"
-                    HorizontalAlignment="Stretch" HorizontalContentAlignment="Left"
-                    Padding="12,9"
-                    Command="{Binding NavigateToSectionCommand}"
-                    CommandParameter="2"/>
-            <Button Content="✋  Mitarbeit"
-                    HorizontalAlignment="Stretch" HorizontalContentAlignment="Left"
-                    Padding="12,9"
-                    Command="{Binding NavigateToSectionCommand}"
-                    CommandParameter="3"/>
-            <Button Content="📝  Klausuren"
-                    HorizontalAlignment="Stretch" HorizontalContentAlignment="Left"
-                    Padding="12,9"
-                    Command="{Binding NavigateToSectionCommand}"
-                    CommandParameter="4"/>
-            <Button Content="🔢  Notenübersicht"
-                    HorizontalAlignment="Stretch" HorizontalContentAlignment="Left"
-                    Padding="12,9"
-                    Command="{Binding NavigateToSectionCommand}"
-                    CommandParameter="5"/>
-            <Button Content="📅  Unterrichtsplanung"
-                    HorizontalAlignment="Stretch" HorizontalContentAlignment="Left"
-                    Padding="12,9"
-                    Command="{Binding NavigateToSectionCommand}"
-                    CommandParameter="6"/>
-            <Button Content="🎯  Kompetenzübersicht"
-                    HorizontalAlignment="Stretch" HorizontalContentAlignment="Left"
-                    Padding="12,9"
-                    Command="{Binding NavigateToSectionCommand}"
-                    CommandParameter="7"/>
-            <Button Content="📋  Dokumentation"
-                    HorizontalAlignment="Stretch" HorizontalContentAlignment="Left"
-                    Padding="12,9"
-                    Command="{Binding NavigateToSectionCommand}"
-                    CommandParameter="8"/>
-          </StackPanel>
-
-        </StackPanel>
       </ScrollViewer>
-
     </Grid>
   </Grid>
 </UserControl>

LehrerApp.Desktop/Views/Groups/TeachingModeWindow.axaml

@@ -27,6 +27,13 @@
         </StackPanel>
       </StackPanel>
       <StackPanel Grid.Column="1" Orientation="Horizontal" Spacing="8" VerticalAlignment="Center">
+        <!-- Nutzer-Feedback: die Schnellbewertungs-Dialoge gab es bisher nur über den
+             Mitarbeit-Tab der Gruppe — hier direkt auf die Sitzung dieser Stunde vorselektiert
+             (siehe TeachingModeViewModel), kein Umweg mehr über "Zur Mitarbeit". -->
+        <Button Content="⚡ Mitarbeit" Command="{Binding Participation.QuickInputCommand}"
+                ToolTip.Tip="Mitarbeit dieser Stunde schnell bewerten."/>
+        <Button Content="⚡ Anwesenheit/Hausaufgabe" Command="{Binding Participation.StatusQuickInputCommand}"
+                ToolTip.Tip="Anwesenheit und Hausaufgabenstatus dieser Stunde schnell erfassen."/>
         <Button Content="Zur Mitarbeit" Command="{Binding LessonInfo.NavigateToParticipationCommand}"
                 ToolTip.Tip="Schließt den Unterrichtsmodus und springt zum Tab 'Mitarbeit' der Lerngruppe."/>
         <Button Content="Zu den Noten" Command="{Binding LessonInfo.NavigateToGradesCommand}"/>
@@ -80,9 +87,32 @@
               </ItemsControl.ItemTemplate>
             </ItemsControl>
 
-            <StackPanel Spacing="4" IsVisible="{Binding LessonInfo.Homework, Converter={x:Static StringConverters.IsNotNullOrEmpty}}">
+            <!-- Nutzer-Feedback: Hausaufgabe der letzten Stunde ansehen/als kontrolliert abhaken
-              <TextBlock Text="Hausaufgabe" FontSize="12" FontWeight="SemiBold" Opacity="0.6"/>
+                 und die Hausaufgabe DIESER Stunde einsehen/ändern, ohne den vollen
-              <TextBlock Text="{Binding LessonInfo.Homework}" FontSize="13" TextWrapping="Wrap"/>
+                 Verlaufsplan-Editor öffnen zu müssen — manchmal ergibt sich die Hausaufgabe erst
+                 während des Unterrichts. Ersetzt die bisherige rein lesbare Anzeige
+                 (LessonInfo.Homework), die dasselbe Feld doppelt und nur lesend gezeigt hätte. -->
+            <Border Background="{DynamicResource SystemControlBackgroundAltHighBrush}"
+                    CornerRadius="6" Padding="10,8" IsVisible="{Binding Homework.HasPreviousHomework}">
+              <StackPanel Spacing="4">
+                <TextBlock FontSize="12" FontWeight="SemiBold" Opacity="0.6">
+                  <Run Text="Hausaufgabe letzte Stunde"/><Run Text=" · "/>
+                  <Run Text="{Binding Homework.PreviousLessonLabel}"/>
+                </TextBlock>
+                <TextBlock Text="{Binding Homework.PreviousHomeworkText}" FontSize="13" TextWrapping="Wrap"/>
+                <CheckBox Content="Kontrolliert" IsChecked="{Binding Homework.PreviousHomeworkChecked}"/>
+              </StackPanel>
+            </Border>
+
+            <StackPanel Spacing="4">
+              <TextBlock Text="Hausaufgabe (diese Stunde)" FontSize="12" FontWeight="SemiBold" Opacity="0.6"/>
+              <TextBox Text="{Binding Homework.CurrentHomework, Mode=TwoWay}" AcceptsReturn="True"
+                       TextWrapping="Wrap" MinHeight="52" PlaceholderText="Noch keine Hausaufgabe eingetragen…"/>
+              <Grid ColumnDefinitions="Auto,*">
+                <Button Grid.Column="0" Content="Speichern" Command="{Binding Homework.SaveCurrentHomeworkCommand}"/>
+                <TextBlock Grid.Column="1" Text="{Binding Homework.SaveStatus}" FontSize="11" Opacity="0.55"
+                           VerticalAlignment="Center" Margin="8,0,0,0"/>
+              </Grid>
             </StackPanel>
 
             <StackPanel Spacing="4" IsVisible="{Binding LessonInfo.Reflection, Converter={x:Static StringConverters.IsNotNullOrEmpty}}">

LehrerApp.Desktop/Views/Groups/TeachingModeWindow.axaml.cs

@@ -16,12 +16,38 @@ public partial class TeachingModeWindow : Window
         // Gleiches Muster wie LessonViewerDialog (4.5.3): Fenster schließt zuerst, dann Sprung
         // über die MainWindowViewModel-Singleton-Navigation in den Ziel-Tab der Gruppe.
         if (DataContext is TeachingModeViewModel vm)
+        {
             vm.LessonInfo.OnNavigateToTab = tabIndex =>
             {
                 Close();
                 App.Services.GetRequiredService<MainWindowViewModel>()
                     .NavigateToGroupDetail(vm.LessonInfo.GroupId, tabIndex);
             };
+            // Nutzer-Feedback: Schnellbewertung (Mitarbeit) und Schnellanwesenheit/Hausaufgabe
+            // direkt aus dem Unterrichtsmodus statt erst zum Mitarbeit-Tab wechseln zu müssen —
+            // dieselben Dialoge wie in ParticipationTabView.axaml.cs, hier auf die zu dieser
+            // Stunde gehörende Sitzung vorselektiert (siehe TeachingModeViewModel-Konstruktor).
+            vm.Participation.OnQuickInput = ShowQuickInputDialog;
+            vm.Participation.OnStatusQuickInput = ShowStatusQuickInputDialog;
+        }
+    }
+
+    private async Task ShowQuickInputDialog(ParticipationTabViewModel tabVm)
+    {
+        if (tabVm.StudentRows.Count == 0) return;
+        var quickVm = new QuickInputViewModel(tabVm.StudentRows.ToList(), tabVm.Aspects.ToList());
+        var dialog = new ParticipationQuickInputDialog { DataContext = quickVm };
+        await dialog.ShowDialog(this);
+        (DataContext as TeachingModeViewModel)?.SeatingPlan.ReloadSeatBadgesFromRepository();
+    }
+
+    private async Task ShowStatusQuickInputDialog(ParticipationTabViewModel tabVm)
+    {
+        if (tabVm.StudentRows.Count == 0 || tabVm.SelectedSession is null) return;
+        var quickVm = new AttendanceHomeworkQuickInputViewModel(tabVm.StudentRows, tabVm.SelectedSessionDisplay);
+        var dialog = new AttendanceHomeworkQuickInputDialog { DataContext = quickVm };
+        await dialog.ShowDialog(this);
+        (DataContext as TeachingModeViewModel)?.SeatingPlan.ReloadSeatBadgesFromRepository();
     }
 
     private void OnClose(object? sender, RoutedEventArgs e) => Close();

LehrerApp.Desktop/Views/Groups/WebUntisClassSelectionDialog.axaml

@@ -0,0 +1,34 @@
+<Window xmlns="https://github.com/avaloniaui"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        xmlns:vm="clr-namespace:LehrerApp.Desktop.ViewModels.Groups"
+        xmlns:svc="clr-namespace:LehrerApp.Desktop.Services"
+        x:Class="LehrerApp.Desktop.Views.Groups.WebUntisClassSelectionDialog"
+        x:DataType="vm:WebUntisClassSelectionViewModel"
+        Title="Schüler aus WebUntis" Width="480" SizeToContent="Height"
+        CanResize="False" WindowStartupLocation="CenterOwner">
+  <Grid RowDefinitions="*,Auto" Margin="24">
+    <StackPanel Grid.Row="0" Spacing="12">
+      <TextBlock Text="WebUntis-Klasse auswählen" Classes="dialogtitle"/>
+      <TextBlock Text="Die Schülerliste wird danach im gewohnten Importdialog geprüft."
+                 FontSize="12" Opacity="0.65" TextWrapping="Wrap"/>
+      <Grid ColumnDefinitions="*,Auto" ColumnSpacing="8">
+        <ComboBox Grid.Column="0" ItemsSource="{Binding SchoolYears}" SelectedItem="{Binding SelectedSchoolYear}">
+          <ComboBox.ItemTemplate><DataTemplate x:DataType="svc:UntisSchoolYearDto"><TextBlock Text="{Binding Name}"/></DataTemplate></ComboBox.ItemTemplate>
+        </ComboBox>
+        <Button Grid.Column="1" Content="Klassen laden" Command="{Binding LoadClassesCommand}" IsEnabled="{Binding !Busy}"/>
+      </Grid>
+      <ComboBox ItemsSource="{Binding Classes}" SelectedItem="{Binding SelectedClass}" PlaceholderText="Klasse auswählen">
+        <ComboBox.ItemTemplate>
+          <DataTemplate x:DataType="svc:UntisClassDto">
+            <TextBlock><Run Text="{Binding Name}"/><Run Text=" — "/><Run Text="{Binding LongName}"/></TextBlock>
+          </DataTemplate>
+        </ComboBox.ItemTemplate>
+      </ComboBox>
+      <TextBlock Text="{Binding Status}" FontSize="12" TextWrapping="Wrap"/>
+    </StackPanel>
+    <Grid Grid.Row="1" ColumnDefinitions="*,8,*" Margin="0,20,0,0">
+      <Button Grid.Column="0" Content="Abbrechen" Click="OnCancel"/>
+      <Button Grid.Column="2" Content="Schülerliste laden" IsEnabled="{Binding CanConfirm}" Click="OnConfirm"/>
+    </Grid>
+  </Grid>
+</Window>

LehrerApp.Desktop/Views/Groups/WebUntisClassSelectionDialog.axaml.cs

@@ -0,0 +1,15 @@
+using Avalonia.Controls;
+using Avalonia.Interactivity;
+using LehrerApp.Desktop.ViewModels.Groups;
+
+namespace LehrerApp.Desktop.Views.Groups;
+
+public partial class WebUntisClassSelectionDialog : Window
+{
+    public WebUntisClassSelectionDialog() => InitializeComponent();
+    private void OnCancel(object? sender, RoutedEventArgs e) => Close(false);
+    private void OnConfirm(object? sender, RoutedEventArgs e)
+    {
+        if (DataContext is WebUntisClassSelectionViewModel { SelectedClass: not null }) Close(true);
+    }
+}

LehrerApp.Desktop/Views/Groups/WebUntisLessonAbsenceComparisonDialog.axaml

@@ -0,0 +1,56 @@
+<Window xmlns="https://github.com/avaloniaui"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        xmlns:vm="clr-namespace:LehrerApp.Desktop.ViewModels.Groups"
+        x:Class="LehrerApp.Desktop.Views.Groups.WebUntisLessonAbsenceComparisonDialog"
+        x:DataType="vm:WebUntisLessonAbsenceComparisonViewModel"
+        Title="Fehlzeiten je Unterricht mit WebUntis abgleichen" Width="1000" Height="640"
+        MinWidth="800" MinHeight="450" WindowStartupLocation="CenterOwner">
+  <Grid RowDefinitions="Auto,Auto,Auto,*,Auto,Auto" Margin="24" RowSpacing="8">
+    <StackPanel Grid.Row="0" Spacing="4">
+      <TextBlock Text="Fehlzeiten je Unterricht mit WebUntis abgleichen" Classes="dialogtitle"/>
+      <TextBlock Text="Nur markierte Zeilen mit einer vorhandenen lokalen Kursstunde werden übernommen. Zeilen ohne automatische Zuordnung bitte manuell einem Kursmitglied zuweisen."
+                 FontSize="12" Opacity="0.65" TextWrapping="Wrap"/>
+    </StackPanel>
+    <StackPanel Grid.Row="1" Orientation="Horizontal" Spacing="8">
+      <DatePicker SelectedDate="{Binding StartDate}"/>
+      <TextBlock Text="bis" VerticalAlignment="Center"/>
+      <DatePicker SelectedDate="{Binding EndDate}"/>
+      <Button Content="Fehlzeiten laden" Command="{Binding LoadCommand}" IsEnabled="{Binding !Busy}"/>
+    </StackPanel>
+    <Grid Grid.Row="2" ColumnDefinitions="Auto,1.2*,1.2*,80,80,1.1*,1.1*" ColumnSpacing="8" Margin="4,0">
+      <TextBlock Grid.Column="1" Text="Name (WebUntis)" FontSize="11" Opacity="0.6"/>
+      <TextBlock Grid.Column="2" Text="Zuordnung" FontSize="11" Opacity="0.6"/>
+      <TextBlock Grid.Column="3" Text="Datum" FontSize="11" Opacity="0.6"/>
+      <TextBlock Grid.Column="4" Text="Zeit" FontSize="11" Opacity="0.6"/>
+      <TextBlock Grid.Column="5" Text="WebUntis-Status" FontSize="11" Opacity="0.6"/>
+      <TextBlock Grid.Column="6" Text="Lokaler Status" FontSize="11" Opacity="0.6"/>
+    </Grid>
+    <ScrollViewer Grid.Row="3">
+      <ItemsControl ItemsSource="{Binding Rows}">
+        <ItemsControl.ItemTemplate>
+          <DataTemplate x:DataType="vm:WebUntisLessonAbsenceRow">
+            <Grid ColumnDefinitions="Auto,1.2*,1.2*,80,80,1.1*,1.1*" ColumnSpacing="8" Margin="0,3">
+              <CheckBox Grid.Column="0" IsChecked="{Binding Selected}" IsEnabled="{Binding CanApply}"/>
+              <TextBlock Grid.Column="1" Text="{Binding UntisStudentName}" VerticalAlignment="Center" TextWrapping="Wrap"/>
+              <ComboBox Grid.Column="2" ItemsSource="{Binding Candidates}" SelectedItem="{Binding AssignedStudent}"
+                        DisplayMemberBinding="{Binding FullName}" PlaceholderText="Schüler wählen…"
+                        HorizontalAlignment="Stretch"/>
+              <TextBlock Grid.Column="3" Text="{Binding DateLabel}" VerticalAlignment="Center"/>
+              <TextBlock Grid.Column="4" Text="{Binding TimeLabel}" VerticalAlignment="Center"/>
+              <TextBlock Grid.Column="5" Text="{Binding UntisStatus}" TextWrapping="Wrap" VerticalAlignment="Center"/>
+              <TextBlock Grid.Column="6" Text="{Binding LocalStatus}" TextWrapping="Wrap" VerticalAlignment="Center"/>
+            </Grid>
+          </DataTemplate>
+        </ItemsControl.ItemTemplate>
+      </ItemsControl>
+    </ScrollViewer>
+    <CheckBox Grid.Row="4" Content="Unbekannte im geladenen Zeitraum auf „Anwesend“ setzen"
+              IsChecked="{Binding MarkUnknownAsPresent}"
+              ToolTip.Tip="Gilt nur für Schüler*innen, die WebUntis für den jeweiligen Tag nicht gemeldet hat und die lokal noch keinen Anwesenheitsstatus haben."/>
+    <Grid Grid.Row="5" ColumnDefinitions="*,Auto,Auto" ColumnSpacing="8">
+      <TextBlock Grid.Column="0" Text="{Binding Status}" FontSize="12" TextWrapping="Wrap" VerticalAlignment="Center"/>
+      <Button Grid.Column="1" Content="Schließen" Click="OnClose"/>
+      <Button Grid.Column="2" Content="Markierte übernehmen" Command="{Binding ApplyCommand}" IsEnabled="{Binding !Busy}"/>
+    </Grid>
+  </Grid>
+</Window>

LehrerApp.Desktop/Views/Groups/WebUntisLessonAbsenceComparisonDialog.axaml.cs

@@ -0,0 +1,10 @@
+using Avalonia.Controls;
+using Avalonia.Interactivity;
+
+namespace LehrerApp.Desktop.Views.Groups;
+
+public partial class WebUntisLessonAbsenceComparisonDialog : Window
+{
+    public WebUntisLessonAbsenceComparisonDialog() => InitializeComponent();
+    private void OnClose(object? sender, RoutedEventArgs e) => Close();
+}

LehrerApp.Desktop/Views/MainWindow.axaml

@@ -13,6 +13,10 @@
         xmlns:vmp="clr-namespace:LehrerApp.Desktop.ViewModels.Planning"
         xmlns:vw="clr-namespace:LehrerApp.Desktop.Views.Workload"
         xmlns:vmw="clr-namespace:LehrerApp.Desktop.ViewModels.Workload"
+        xmlns:vct="clr-namespace:LehrerApp.Desktop.Views.ClassTeacher"
+        xmlns:vmct="clr-namespace:LehrerApp.Desktop.ViewModels.ClassTeacher"
+        xmlns:vex="clr-namespace:LehrerApp.Desktop.Views.Exams"
+        xmlns:vmex="clr-namespace:LehrerApp.Desktop.ViewModels.Exams"
         xmlns:svc="clr-namespace:LehrerApp.Desktop.Services"
         x:Class="LehrerApp.Desktop.Views.MainWindow"
         x:DataType="vm:MainWindowViewModel"
@@ -58,6 +62,12 @@
       <DataTemplate DataType="vmw:WorkloadViewModel">
         <vw:WorkloadView/>
       </DataTemplate>
+      <DataTemplate DataType="vmct:ClassTeacherOverviewViewModel">
+        <vct:ClassTeacherOverviewView/>
+      </DataTemplate>
+      <DataTemplate DataType="vmex:ExamsOverviewViewModel">
+        <vex:ExamsOverviewView/>
+      </DataTemplate>
       <DataTemplate DataType="vm:PlaceholderViewModel">
         <views:PlaceholderView/>
       </DataTemplate>
@@ -141,6 +151,20 @@
 
         <ScrollViewer>
           <StackPanel Classes="navitems" Margin="8,12,8,0" Spacing="2">
+            <Button Classes="navitem" HorizontalAlignment="Stretch"
+                    HorizontalContentAlignment="Left" CornerRadius="6"
+                    Click="OnOpenCommandPaletteClick"
+                    ToolTip.Tip="Suchen und schnell erfassen (Strg/⌘+K)"
+                    AutomationProperties.Name="Suchen und schnell erfassen">
+              <Grid ColumnDefinitions="Auto,*,Auto">
+                <TextBlock Classes="navicon" Text="⌕" TextAlignment="Center"/>
+                <TextBlock Grid.Column="1" Classes="navlabel" Text="Suchen / Erfassen"/>
+                <TextBlock Grid.Column="2" Classes="navlabel" Text="⌘K" FontSize="10" Opacity="0.45"
+                           VerticalAlignment="Center"/>
+              </Grid>
+            </Button>
+            <Separator Margin="4,6"/>
+
             <Button Classes="navitem" Classes.active="{Binding IsDashboardActive}" HorizontalAlignment="Stretch"
                     HorizontalContentAlignment="Left"
                     CornerRadius="6"
@@ -209,6 +233,16 @@
                 <TextBlock Classes="navlabel" Text="Arbeitszeit"/>
               </StackPanel>
             </Button>
+            <Button Classes="navitem" Classes.active="{Binding IsClassTeacherActive}" HorizontalAlignment="Stretch"
+                    HorizontalContentAlignment="Left"
+                    CornerRadius="6"
+                    Command="{Binding NavigateToCommand}"
+                    CommandParameter="{x:Static vm:NavItem.ClassTeacher}">
+              <StackPanel Classes="navcontent" Orientation="Horizontal" Spacing="10">
+                <TextBlock Classes="navicon" Text="🎓" TextAlignment="Center"/>
+                <TextBlock Classes="navlabel" Text="Klassenlehrer"/>
+              </StackPanel>
+            </Button>
             <Button Classes="navitem" Classes.active="{Binding IsSettingsActive}" HorizontalAlignment="Stretch"
                     HorizontalContentAlignment="Left"
                     CornerRadius="6"
@@ -226,6 +260,77 @@
 
   </DrawerPage>
 
+  <!-- Globale Suche und Schnellerfassung (14.2). Bewusst als Overlay auf der aktuellen Seite:
+       Der Nutzer behält den Kontext und kann mit Escape ohne Navigation zurückkehren. -->
+  <Border Background="#A0000000" IsVisible="{Binding IsCommandPaletteOpen}"
+          AutomationProperties.Name="Globale Suche und Schnellerfassung">
+    <Grid>
+      <Button Background="Transparent" BorderThickness="0"
+              Command="{Binding CloseCommandPaletteCommand}"
+              AutomationProperties.Name="Suche schließen"/>
+      <Border Width="680" MaxHeight="570" Margin="24" Padding="0"
+              HorizontalAlignment="Center" VerticalAlignment="Top"
+              Background="{DynamicResource AppCardBackgroundBrush}"
+              BorderBrush="{DynamicResource AppCardBorderBrush}" BorderThickness="1"
+              CornerRadius="12">
+        <Grid RowDefinitions="Auto,Auto,*,Auto">
+          <Grid Grid.Row="0" ColumnDefinitions="Auto,*,Auto" Margin="18,16,18,10">
+            <TextBlock Text="⌕" FontSize="24" VerticalAlignment="Center" Margin="0,0,10,0"/>
+            <TextBox x:Name="CommandPaletteSearchBox" Grid.Column="1"
+                     Text="{Binding CommandPalette.Query, UpdateSourceTrigger=PropertyChanged}"
+                     PlaceholderText="Schüler, Lerngruppe, Klausur oder Aufgabe suchen …"
+                     FontSize="16" BorderThickness="0" Background="Transparent"
+                     AutomationProperties.Name="Suchbegriff"/>
+            <Button Grid.Column="2" Content="Esc" FontSize="10" Padding="8,3"
+                    Command="{Binding CloseCommandPaletteCommand}"
+                    AutomationProperties.Name="Suche schließen"/>
+          </Grid>
+          <Separator Grid.Row="1"/>
+          <ListBox Grid.Row="2" ItemsSource="{Binding CommandPalette.Results}"
+                   SelectedItem="{Binding CommandPalette.SelectedResult}"
+                   Background="Transparent" BorderThickness="0" Margin="8"
+                   MaxHeight="420">
+            <ListBox.ItemTemplate>
+              <DataTemplate x:DataType="vm:GlobalSearchResult">
+                <Button Background="Transparent" BorderThickness="0" Padding="10,8"
+                        HorizontalAlignment="Stretch" HorizontalContentAlignment="Stretch"
+                        Command="{Binding $parent[Window].((vm:MainWindowViewModel)DataContext).CommandPalette.ExecuteCommand}"
+                        CommandParameter="{Binding}">
+                  <Grid ColumnDefinitions="38,*,Auto">
+                    <Border Width="30" Height="30" CornerRadius="7"
+                            Background="{DynamicResource AppAccentSoftBackgroundBrush}"
+                            VerticalAlignment="Center">
+                      <TextBlock Text="{Binding Icon}" FontWeight="SemiBold"
+                                 Foreground="{DynamicResource AppAccentOnSoftBrush}"
+                                 HorizontalAlignment="Center" VerticalAlignment="Center"/>
+                    </Border>
+                    <StackPanel Grid.Column="1" Margin="10,0">
+                      <TextBlock Text="{Binding Title}" FontSize="14" FontWeight="SemiBold"/>
+                      <TextBlock Text="{Binding Subtitle}" FontSize="11" Opacity="0.6"
+                                 TextTrimming="CharacterEllipsis"/>
+                    </StackPanel>
+                    <Border Grid.Column="2" Padding="7,3" CornerRadius="8"
+                            Background="{DynamicResource AppChipBackgroundBrush}"
+                            VerticalAlignment="Center">
+                      <TextBlock Text="{Binding KindLabel}" FontSize="10" Opacity="0.7"/>
+                    </Border>
+                  </Grid>
+                </Button>
+              </DataTemplate>
+            </ListBox.ItemTemplate>
+          </ListBox>
+          <TextBlock Grid.Row="2" Text="Keine passenden Ergebnisse."
+                     Classes="emptyhint" HorizontalAlignment="Center" Margin="20"
+                     IsVisible="{Binding CommandPalette.ShowNoResults}"/>
+          <Grid Grid.Row="3" ColumnDefinitions="*,Auto" Margin="18,8,18,14">
+            <TextBlock Text="↑↓ auswählen · Enter öffnen · Esc schließen" FontSize="10" Opacity="0.5"/>
+            <TextBlock Grid.Column="1" Text="Strg/⌘ + K" FontSize="10" Opacity="0.5"/>
+          </Grid>
+        </Grid>
+      </Border>
+    </Grid>
+  </Border>
+
   <!-- Dauerhafte Meldung bei einer echten Protokoll-Inkompatibilität. Als Overlay außerhalb
        von DrawerPage.Content bleibt der DataContext das MainWindowViewModel; innerhalb des
        ContentPresenters würde eine fehlgeschlagene Bindung IsVisible auf true stehen lassen. -->

LehrerApp.Desktop/Views/MainWindow.axaml.cs

@@ -1,5 +1,6 @@
 using Avalonia.Controls;
 using Avalonia.Input;
+using Avalonia.Threading;
 using LehrerApp.Desktop.Services;
 using LehrerApp.Desktop.ViewModels;
 using LehrerApp.Sync;
@@ -19,6 +20,62 @@ public partial class MainWindow : Window
         PointerMoved   += (_, _) => NotifyActivity();
         PointerPressed += (_, _) => NotifyActivity();
         KeyDown        += (_, _) => NotifyActivity();
+        KeyDown        += OnWindowKeyDown;
+    }
+
+    private void OnWindowKeyDown(object? sender, KeyEventArgs e)
+    {
+        if (DataContext is not MainWindowViewModel vm) return;
+
+        var commandModifier = (e.KeyModifiers & (KeyModifiers.Control | KeyModifiers.Meta)) != 0;
+        if (commandModifier && e.Key == Key.K)
+        {
+            vm.OpenCommandPaletteCommand.Execute(null);
+            FocusCommandPalette();
+            e.Handled = true;
+            return;
+        }
+
+        if (!vm.IsCommandPaletteOpen) return;
+        if (e.Key == Key.Escape)
+        {
+            vm.CloseCommandPaletteCommand.Execute(null);
+            e.Handled = true;
+        }
+        else if (e.Key == Key.Enter)
+        {
+            vm.CommandPalette.ExecuteCommand.Execute(vm.CommandPalette.SelectedResult);
+            e.Handled = true;
+        }
+        else if (e.Key is Key.Down or Key.Up)
+        {
+            MoveCommandPaletteSelection(vm, e.Key == Key.Down ? 1 : -1);
+            e.Handled = true;
+        }
+    }
+
+    private void OnOpenCommandPaletteClick(object? sender, Avalonia.Interactivity.RoutedEventArgs e)
+    {
+        if (DataContext is MainWindowViewModel vm)
+            vm.OpenCommandPaletteCommand.Execute(null);
+        FocusCommandPalette();
+    }
+
+    private void FocusCommandPalette() => Dispatcher.UIThread.Post(() =>
+    {
+        if (this.FindControl<TextBox>("CommandPaletteSearchBox") is { } search)
+        {
+            search.Focus();
+            search.SelectAll();
+        }
+    });
+
+    private static void MoveCommandPaletteSelection(MainWindowViewModel vm, int delta)
+    {
+        var results = vm.CommandPalette.Results;
+        if (results.Count == 0) return;
+        var current = vm.CommandPalette.SelectedResult is { } selected ? results.IndexOf(selected) : -1;
+        vm.CommandPalette.SelectedResult = results[Math.Clamp(current + delta, 0, results.Count - 1)];
     }
 
     public void EnableFinalSync(SyncEngine syncEngine)

LehrerApp.Desktop/Views/Planning/TimetableView.axaml

@@ -21,6 +21,21 @@
     <Style Selector="Border.supervisioncell.substitution">
       <Setter Property="Background" Value="#8E24AA"/>
     </Style>
+    <Style Selector="Button.weekCellMenuTrigger">
+      <Setter Property="Width" Value="18"/>
+      <Setter Property="Height" Value="16"/>
+      <Setter Property="Padding" Value="0"/>
+      <Setter Property="Margin" Value="2"/>
+      <Setter Property="Background" Value="#33000000"/>
+      <Setter Property="Foreground" Value="White"/>
+      <Setter Property="FontSize" Value="11"/>
+      <Setter Property="CornerRadius" Value="4"/>
+      <Setter Property="HorizontalContentAlignment" Value="Center"/>
+      <Setter Property="VerticalContentAlignment" Value="Center"/>
+    </Style>
+    <Style Selector="Button.weekCellMenuTrigger:pointerover /template/ ContentPresenter">
+      <Setter Property="Background" Value="#55000000"/>
+    </Style>
   </UserControl.Styles>
 
   <Grid RowDefinitions="Auto,Auto,*">
@@ -226,36 +241,65 @@
                             </Border>
                             <Border Classes="timetablecell" Classes.assigned="{Binding IsAssigned}"
                                     CornerRadius="6" IsVisible="{Binding IsSlotCell}">
-                              <Button Background="{Binding ColorHex}" IsVisible="{Binding IsAssigned}"
+                              <Panel IsVisible="{Binding IsAssigned}">
-                                      HorizontalAlignment="Stretch" VerticalAlignment="Stretch"
+                                <Button Background="{Binding ColorHex}"
-                                      HorizontalContentAlignment="Stretch" CornerRadius="6" Padding="6"
+                                        HorizontalAlignment="Stretch" VerticalAlignment="Stretch"
-                                      Command="{Binding $parent[ItemsControl;1].((vm:TimetableViewModel)DataContext).OpenWeekCellCommand}"
+                                        HorizontalContentAlignment="Stretch" CornerRadius="6" Padding="6"
-                                      CommandParameter="{Binding}">
+                                        Command="{Binding $parent[ItemsControl;1].((vm:TimetableViewModel)DataContext).OpenWeekCellCommand}"
-                                <StackPanel Spacing="1">
+                                        CommandParameter="{Binding}">
-                                  <TextBlock FontSize="11" FontWeight="Bold" Foreground="White" TextWrapping="Wrap">
+                                  <StackPanel Spacing="1">
-                                    <Run Text="{Binding SubjectLabel}"/><Run Text=" · "/><Run Text="{Binding GroupName}"/>
+                                    <TextBlock FontSize="11" FontWeight="Bold" Foreground="White" TextWrapping="Wrap">
-                                  </TextBlock>
+                                      <Run Text="{Binding SubjectLabel}"/><Run Text=" · "/><Run Text="{Binding GroupName}"/>
-                                  <TextBlock Text="{Binding Room}" FontSize="10" Foreground="White" Opacity="0.9"
+                                    </TextBlock>
-                                             IsVisible="{Binding HasRoom}"/>
+                                    <TextBlock Text="{Binding Room}" FontSize="10" Foreground="White" Opacity="0.9"
-                                  <TextBlock Text="{Binding Topic}" FontSize="10" Foreground="White" Opacity="0.8"
+                                               IsVisible="{Binding HasRoom}"/>
-                                             TextWrapping="Wrap" IsVisible="{Binding HasTopic}"/>
+                                    <TextBlock Text="{Binding Topic}" FontSize="10" Foreground="White" Opacity="0.8"
-                                  <TextBlock Text="Ferien" FontSize="10" Foreground="White" FontWeight="SemiBold"
+                                               TextWrapping="Wrap" IsVisible="{Binding HasTopic}"/>
-                                             Opacity="0.9" IsVisible="{Binding IsHoliday}" Margin="0,2,0,0"/>
+                                    <TextBlock Text="Ferien" FontSize="10" Foreground="White" FontWeight="SemiBold"
-                                  <TextBlock Text="Ausfall" FontSize="10" Foreground="White" FontWeight="SemiBold"
+                                               Opacity="0.9" IsVisible="{Binding IsHoliday}" Margin="0,2,0,0"/>
-                                             Opacity="0.9" IsVisible="{Binding IsCancelled}" Margin="0,2,0,0"/>
+                                    <TextBlock Text="Ausfall" FontSize="10" Foreground="White" FontWeight="SemiBold"
-                                  <StackPanel Orientation="Horizontal" Spacing="3" Margin="0,2,0,0"
+                                               Opacity="0.9" IsVisible="{Binding IsCancelled}" Margin="0,2,0,0"/>
-                                              IsVisible="{Binding !IsHoliday}">
+                                    <StackPanel Orientation="Horizontal" Spacing="3" Margin="0,2,0,0"
-                                    <Border Background="#B71C1C" CornerRadius="7" Padding="4,0" IsVisible="{Binding HasHolidayBadge}">
+                                                IsVisible="{Binding !IsHoliday}">
-                                      <TextBlock Text="{Binding HolidayBadge}" FontSize="9" FontWeight="Bold" Foreground="White"/>
+                                      <Border Background="#B71C1C" CornerRadius="7" Padding="4,0" IsVisible="{Binding HasHolidayBadge}">
-                                    </Border>
+                                        <TextBlock Text="{Binding HolidayBadge}" FontSize="9" FontWeight="Bold" Foreground="White"/>
-                                    <TextBlock Text="📝" FontSize="11" IsVisible="{Binding HasExam}" ToolTip.Tip="Klausur"/>
+                                      </Border>
-                                    <TextBlock Text="⏰" FontSize="11" IsVisible="{Binding IsLastBeforeExam}" ToolTip.Tip="Letzte Stunde vor der Klausur"/>
+                                      <TextBlock Text="📝" FontSize="11" IsVisible="{Binding HasExam}" ToolTip.Tip="Klausur"/>
-                                    <TextBlock Text="🧪" FontSize="11" IsVisible="{Binding HasExperiment}" ToolTip.Tip="Experiment geplant"/>
+                                      <TextBlock Text="⏰" FontSize="11" IsVisible="{Binding IsLastBeforeExam}" ToolTip.Tip="Letzte Stunde vor der Klausur"/>
-                                    <TextBlock Text="📓" FontSize="11" IsVisible="{Binding HasUnhandledHomework}"
+                                      <TextBlock Text="🧪" FontSize="11" IsVisible="{Binding HasExperiment}" ToolTip.Tip="Experiment geplant"/>
-                                               ToolTip.Tip="Hausaufgabe aus letzter Stunde noch nicht kontrolliert"/>
+                                      <TextBlock Text="📓" FontSize="11" IsVisible="{Binding HasUnhandledHomework}"
+                                                 ToolTip.Tip="Hausaufgabe aus letzter Stunde noch nicht kontrolliert"/>
+                                    </StackPanel>
                                   </StackPanel>
-                                </StackPanel>
+                                </Button>
-                              </Button>
+                                <!-- Nutzer-Feedback (zweite Runde): Popup-Menü statt Dropdown, hier
+                                     im Wochenraster statt in der Tagesliste (dort waren die
+                                     bisherigen zwei Buttons schon in Ordnung). Sibling-Button statt
+                                     verschachteltem Button/ContextMenu — Routing über
+                                     MenuItem.Click in TimetableView.axaml.cs, siehe Kommentar dort
+                                     zu DataContext-Vererbung vs. $parent-Vorfahrensuche im Flyout. -->
+                                <Button Classes="weekCellMenuTrigger" Content="⋮"
+                                        HorizontalAlignment="Right" VerticalAlignment="Top"
+                                        IsVisible="{Binding HasGroupId}"
+                                        ToolTip.Tip="Weitere Ziele…">
+                                  <Button.Flyout>
+                                    <MenuFlyout Placement="BottomEdgeAlignedRight">
+                                      <MenuItem Header="▶ Unterrichtsansicht" IsVisible="{Binding HasLesson}"
+                                                Tag="{x:Static vm:TimetableLessonDestination.TeachingMode}"
+                                                Click="OnWeekCellMenuItemClick"/>
+                                      <MenuItem Header="📋 Planungsviewer" IsVisible="{Binding HasLesson}"
+                                                Tag="{x:Static vm:TimetableLessonDestination.Viewer}"
+                                                Click="OnWeekCellMenuItemClick"/>
+                                      <MenuItem Header="🪑 Sitzplan"
+                                                Tag="{x:Static vm:TimetableLessonDestination.SeatingPlan}"
+                                                Click="OnWeekCellMenuItemClick"/>
+                                      <MenuItem Header="✏️ Planung"
+                                                Tag="{x:Static vm:TimetableLessonDestination.Planning}"
+                                                Click="OnWeekCellMenuItemClick"/>
+                                    </MenuFlyout>
+                                  </Button.Flyout>
+                                </Button>
+                              </Panel>
                             </Border>
                           </Grid>
                         </DataTemplate>
@@ -308,6 +352,11 @@
       <ContentPage Header="Bearbeiten">
         <ScrollViewer>
           <StackPanel Margin="32,20,32,28" Spacing="10">
+            <StackPanel Orientation="Horizontal" Spacing="8" Margin="0,0,0,6">
+              <Button Content="Aus WebUntis laden…" Command="{Binding ImportWebUntisTimetableCommand}"/>
+              <TextBlock Text="Importiert oder vergleicht eine typische Unterrichtswoche; Vertretungen bleiben im iCal-Abgleich."
+                         FontSize="11" Opacity="0.6" VerticalAlignment="Center"/>
+            </StackPanel>
             <!-- Zeilenweise (GridRows) statt eines flachen UniformGrid, siehe Kommentar im
                  Wochenraster oben (Heute-Tab) - gleicher Grund (Grid.RowDefinitions lässt sich
                  nicht per {Binding} setzen). -->

LehrerApp.Desktop/Views/Planning/TimetableView.axaml.cs

@@ -1,10 +1,13 @@
 using Avalonia.Controls;
+using Avalonia.Interactivity;
 using LehrerApp.Core.Interfaces;
 using LehrerApp.Core.Models;
 using LehrerApp.Core.Services;
+using LehrerApp.Desktop.ViewModels;
 using LehrerApp.Desktop.ViewModels.Planning;
 using LehrerApp.Desktop.ViewModels.Groups;
 using LehrerApp.Desktop.Views.Groups;
+using LehrerApp.Desktop.Services;
 using Microsoft.Extensions.DependencyInjection;
 
 namespace LehrerApp.Desktop.Views.Planning;
@@ -20,11 +23,67 @@ public partial class TimetableView : UserControl
         {
             vm.OnEditSlot = ShowSlotDialog;
             vm.OnAddSubstitution = ShowSubstitutionDialog;
+            vm.OnImportWebUntisTimetable = ShowWebUntisTimetableDialog;
             vm.OnOpenLessonViewer = ShowLessonViewerDialog;
             vm.OnOpenTeachingMode = ShowTeachingMode;
         }
     }
 
+    /// Nutzer-Feedback (zweite Runde — die erste Fassung hatte das Problem an der falschen
+    /// Stelle gelöst, in der "Heute"-Tagesliste statt im Wochenraster): im Wochenraster oben
+    /// führt ein Klick auf eine Stunden-Kachel bislang entweder in den Planungsviewer oder zur
+    /// Einheitenplanung — je nachdem, ob schon eine Lesson existiert, ohne dass das von außen
+    /// erkennbar wäre. Popup-Menü (MenuFlyout, kein ComboBox mehr) mit allen vier Zielen als
+    /// Alternative zum Direktklick, siehe <see cref="TimetableViewModel.OpenWeekCellCommand"/>
+    /// für den "einheitlicheren" Standard-Klick (Unterrichtsansicht bei laufender Stunde, sonst
+    /// Planungsviewer, sonst Einheitenplanung). MenuItem.Click statt Command-Binding: ein
+    /// $parent[ItemsControl]-Vorfahrenpfad (wie beim Zeilen-Button) funktioniert innerhalb eines
+    /// Flyouts nicht zuverlässig, weil dessen Popup nicht im normalen visuellen Baum hängt (siehe
+    /// TODO.md-Nachtrag zum Klassenlehrer-Bereich) — DataContext-Vererbung (kein Pfad-Suchen,
+    /// nur der normale Eltern-Wert) funktioniert dort aber sehr wohl, deshalb liest der Handler
+    /// die Zelle über <c>((MenuItem)sender).DataContext</c> statt über eine Binding.
+    private async void OnWeekCellMenuItemClick(object? sender, RoutedEventArgs e)
+    {
+        if (sender is not MenuItem { Tag: TimetableLessonDestination destination } menuItem) return;
+        if (menuItem.DataContext is not WeekCellItem cell) return;
+        if (DataContext is not TimetableViewModel vm) return;
+
+        switch (destination)
+        {
+            case TimetableLessonDestination.TeachingMode:
+                if (cell.Lesson is { } teachLesson && vm.OnOpenTeachingMode is not null)
+                    await vm.OnOpenTeachingMode(teachLesson);
+                break;
+            case TimetableLessonDestination.Viewer:
+                if (cell.Lesson is { } viewLesson && vm.OnOpenLessonViewer is not null)
+                    await vm.OnOpenLessonViewer(viewLesson);
+                break;
+            case TimetableLessonDestination.Planning:
+                if (cell.GroupId != Guid.Empty)
+                    App.Services.GetRequiredService<MainWindowViewModel>().NavigateToGroupDetail(cell.GroupId, 6);
+                break;
+            case TimetableLessonDestination.SeatingPlan:
+                if (cell.GroupId != Guid.Empty)
+                    App.Services.GetRequiredService<MainWindowViewModel>().NavigateToGroupDetail(cell.GroupId, 2);
+                break;
+        }
+    }
+
+    private async Task ShowWebUntisTimetableDialog()
+    {
+        var owner = TopLevel.GetTopLevel(this) as Window;
+        if (owner is null) return;
+        var vm = new WebUntisTimetableImportViewModel(
+            App.Services.GetRequiredService<WebUntisIntegrationService>(),
+            App.Services.GetRequiredService<WebUntisSettingsService>(),
+            App.Services.GetRequiredService<ITimetableSlotRepository>(),
+            App.Services.GetRequiredService<IGroupRepository>());
+        var dialog = new WebUntisTimetableImportDialog { DataContext = vm };
+        vm.OnCreateGroup = dialog.CreateGroupAsync;
+        await vm.InitializeAsync();
+        await dialog.ShowDialog<bool>(owner);
+    }
+
     private async Task ShowTeachingMode(Lesson lesson)
     {
         var owner = TopLevel.GetTopLevel(this) as Window;
@@ -33,7 +92,9 @@ public partial class TimetableView : UserControl
 
         var teachingModeVm = new TeachingModeViewModel(lesson, group,
             App.Services.GetRequiredService<IAlternativeLessonPathRepository>(),
-            App.Services.GetRequiredService<SeatingPlanTabViewModel>());
+            App.Services.GetRequiredService<ILessonRepository>(),
+            App.Services.GetRequiredService<SeatingPlanTabViewModel>(),
+            App.Services.GetRequiredService<ParticipationTabViewModel>());
         var window = new TeachingModeWindow { DataContext = teachingModeVm };
         await window.ShowDialog(owner);
     }

LehrerApp.Desktop/Views/Planning/WebUntisTimetableImportDialog.axaml

@@ -0,0 +1,56 @@
+<Window xmlns="https://github.com/avaloniaui"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        xmlns:vm="clr-namespace:LehrerApp.Desktop.ViewModels.Planning"
+        xmlns:svc="clr-namespace:LehrerApp.Desktop.Services"
+        x:Class="LehrerApp.Desktop.Views.Planning.WebUntisTimetableImportDialog"
+        x:DataType="vm:WebUntisTimetableImportViewModel"
+        Title="Stundenplan aus WebUntis" Width="820" Height="650"
+        MinWidth="680" MinHeight="480" WindowStartupLocation="CenterOwner">
+  <Grid RowDefinitions="Auto,Auto,*,Auto" Margin="24" RowSpacing="14">
+    <StackPanel Grid.Row="0" Spacing="4">
+      <TextBlock Text="Stundenplan aus WebUntis" Classes="dialogtitle"/>
+      <TextBlock Text="Wähle eine typische Unterrichtswoche. Vorhandene Einträge werden vorgeschlagen und erst nach Bestätigung ersetzt."
+                 FontSize="12" Opacity="0.65" TextWrapping="Wrap"/>
+    </StackPanel>
+    <Grid Grid.Row="1" ColumnDefinitions="2*,*,Auto" ColumnSpacing="10">
+      <ComboBox Grid.Column="0" ItemsSource="{Binding Teachers}" SelectedItem="{Binding SelectedTeacher}">
+        <ComboBox.ItemTemplate>
+          <DataTemplate x:DataType="svc:UntisTeacherDto"><TextBlock Text="{Binding DisplayName}"/></DataTemplate>
+        </ComboBox.ItemTemplate>
+      </ComboBox>
+      <DatePicker Grid.Column="1" SelectedDate="{Binding WeekDate}"/>
+      <Button Grid.Column="2" Content="Woche laden" Command="{Binding LoadCommand}" IsEnabled="{Binding !Busy}"/>
+    </Grid>
+    <ScrollViewer Grid.Row="2">
+      <ItemsControl ItemsSource="{Binding Rows}">
+        <ItemsControl.ItemTemplate>
+          <DataTemplate x:DataType="vm:WebUntisTimetableRow">
+            <Grid ColumnDefinitions="48,85,2*,2*,Auto" ColumnSpacing="8" Margin="0,3">
+              <TextBlock Grid.Column="0" Text="{Binding WeekdayLabel}" VerticalAlignment="Center" FontWeight="SemiBold"/>
+              <StackPanel Grid.Column="1">
+                <TextBlock Text="{Binding PeriodNumber, StringFormat={}{0}. Std.}" FontSize="12"/>
+                <TextBlock Text="{Binding TimeLabel}" FontSize="10" Opacity="0.6"/>
+              </StackPanel>
+              <TextBlock Grid.Column="2" Text="{Binding UntisLabel}" TextWrapping="Wrap" VerticalAlignment="Center"/>
+              <ComboBox Grid.Column="3" ItemsSource="{Binding GroupOptions}" SelectedItem="{Binding SelectedGroup}"
+                        PlaceholderText="nicht übernehmen">
+                <ComboBox.ItemTemplate>
+                  <DataTemplate x:DataType="vm:WebUntisGroupOption"><TextBlock Text="{Binding DisplayName}"/></DataTemplate>
+                </ComboBox.ItemTemplate>
+              </ComboBox>
+              <Button Grid.Column="4" Content="Neue Gruppe…" FontSize="11"
+                      Command="{Binding $parent[ItemsControl].((vm:WebUntisTimetableImportViewModel)DataContext).CreateGroupCommand}"
+                      CommandParameter="{Binding}"/>
+            </Grid>
+          </DataTemplate>
+        </ItemsControl.ItemTemplate>
+      </ItemsControl>
+    </ScrollViewer>
+    <Grid Grid.Row="3" ColumnDefinitions="*,Auto,Auto" ColumnSpacing="8">
+      <TextBlock Grid.Column="0" Text="{Binding Status}" FontSize="12" TextWrapping="Wrap" VerticalAlignment="Center"/>
+      <Button Grid.Column="1" Content="Abbrechen" Click="OnCancel"/>
+      <Button Grid.Column="2" Content="Zuordnung übernehmen" Command="{Binding SaveCommand}" Click="OnSave"
+              IsEnabled="{Binding !Busy}"/>
+    </Grid>
+  </Grid>
+</Window>

LehrerApp.Desktop/Views/Planning/WebUntisTimetableImportDialog.axaml.cs

@@ -0,0 +1,36 @@
+using Avalonia.Controls;
+using Avalonia.Interactivity;
+using LehrerApp.Core.Models;
+using LehrerApp.Desktop.ViewModels.Groups;
+using LehrerApp.Desktop.ViewModels.Planning;
+using LehrerApp.Desktop.Views.Groups;
+using Microsoft.Extensions.DependencyInjection;
+
+namespace LehrerApp.Desktop.Views.Planning;
+
+public partial class WebUntisTimetableImportDialog : Window
+{
+    public WebUntisTimetableImportDialog() => InitializeComponent();
+
+    private void OnCancel(object? sender, RoutedEventArgs e) => Close(false);
+    private void OnSave(object? sender, RoutedEventArgs e)
+    {
+        if (DataContext is WebUntisTimetableImportViewModel { Saved: true }) Close(true);
+    }
+
+    public async Task<LearningGroup?> CreateGroupAsync(WebUntisTimetableRow source)
+    {
+        var vm = App.Services.GetRequiredService<AddGroupDialogViewModel>();
+        vm.Name = source.SuggestedGroupName;
+        vm.Subject = source.SubjectName ?? "";
+        vm.GradeLevel = ParseGrade(source.SuggestedGroupName) ?? 10;
+        var dialog = new AddGroupDialog { DataContext = vm };
+        return await dialog.ShowDialog<bool>(this) ? vm.Result : null;
+    }
+
+    private static int? ParseGrade(string value)
+    {
+        var digits = new string(value.TakeWhile(char.IsDigit).ToArray());
+        return int.TryParse(digits, out var grade) && grade is >= 1 and <= 13 ? grade : null;
+    }
+}

LehrerApp.Desktop/Views/Settings/SettingsView.axaml

@@ -967,7 +967,53 @@
 
             <TextBlock Text="Untis-Einbettung" FontSize="18" FontWeight="SemiBold"/>
             <TextBlock FontSize="12" Opacity="0.6" TextWrapping="Wrap"
-                       Text="Bindet den persönlichen WebUntis-Stundenplan und den schulweiten Jahresplan als zwei unabhängige iCal-Quellen ein."/>
+                       Text="Bindet WebUntis-Daten über deinen persönlichen Zugang ein. Der bestehende iCal-Abgleich für Vertretungen bleibt davon unabhängig."/>
+
+            <TextBlock Text="WebUntis-API" FontSize="16" FontWeight="SemiBold"/>
+            <TextBlock FontSize="12" Opacity="0.6" TextWrapping="Wrap"
+                       Text="Ermöglicht Stundenplan-, Schüler- und Fehlzeitenabgleich direkt zwischen diesem Gerät und WebUntis. Zugangsdaten werden lokal verschlüsselt gespeichert; weder sie noch Schülerdaten oder CSV-Reports passieren den LehrerApp-Server."/>
+            <Grid ColumnDefinitions="*,*" RowDefinitions="Auto,Auto" ColumnSpacing="8" RowSpacing="8">
+              <StackPanel Grid.Row="0" Grid.Column="0" Spacing="4">
+                <TextBlock Text="Schule" FontSize="12" Opacity="0.7"/>
+                <TextBox Text="{Binding UntisSchool}" PlaceholderText="Schulkennung, nicht Anzeigename"/>
+              </StackPanel>
+              <StackPanel Grid.Row="0" Grid.Column="1" Spacing="4">
+                <TextBlock Text="Server (optional)" FontSize="12" Opacity="0.7"/>
+                <TextBox Text="{Binding UntisHost}" PlaceholderText="z. B. arche.webuntis.com"/>
+              </StackPanel>
+              <StackPanel Grid.Row="1" Grid.Column="0" Spacing="4">
+                <TextBlock Text="Benutzername" FontSize="12" Opacity="0.7"/>
+                <TextBox Text="{Binding UntisUsername}"/>
+              </StackPanel>
+              <StackPanel Grid.Row="1" Grid.Column="1" Spacing="4">
+                <TextBlock Text="Passwort" FontSize="12" Opacity="0.7"/>
+                <TextBox Text="{Binding UntisPassword}" PasswordChar="●"/>
+              </StackPanel>
+            </Grid>
+            <TextBlock FontSize="11" Opacity="0.6" TextWrapping="Wrap"
+                       Text="Die Schulkennung steht in der WebUntis-Anmelde-URL hinter ?school=. Als Server kannst du auch die vollständige Anmelde-URL einfügen; Server und Schulkennung sind häufig verschieden."/>
+            <TextBlock Text="{Binding UntisApiStatus}" FontSize="12" TextWrapping="Wrap"/>
+            <StackPanel Orientation="Horizontal" Spacing="8">
+              <Button Content="Anmeldung prüfen und speichern" Command="{Binding UntisSaveApiCommand}"
+                      IsEnabled="{Binding !UntisApiBusy}"/>
+              <Button Content="API-Zugang entfernen" Command="{Binding UntisRemoveApiCommand}"
+                      IsVisible="{Binding UntisApiIsConfigured}" IsEnabled="{Binding !UntisApiBusy}"/>
+            </StackPanel>
+
+            <StackPanel Spacing="8" IsVisible="{Binding UntisApiIsConfigured}">
+              <Separator Margin="0,8"/>
+              <TextBlock Text="Klassenlehrer" FontSize="16" FontWeight="SemiBold"/>
+              <TextBlock FontSize="12" Opacity="0.6" TextWrapping="Wrap"
+                         Text="Die Klasse, deren Klassenlehrer/-in du bist — unabhängig von deinem eigenen Unterricht. Schaltet den Klassenlehrer-Bereich in der Seitenleiste frei."/>
+              <TextBlock FontSize="13" Text="{Binding UntisHomeroomClassDisplay}"/>
+              <StackPanel Orientation="Horizontal" Spacing="8">
+                <Button Content="Klasse auswählen…" Command="{Binding UntisPickHomeroomClassCommand}"/>
+                <Button Content="Entfernen" Command="{Binding UntisClearHomeroomClassCommand}"
+                        IsVisible="{Binding UntisHomeroomClassName, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"/>
+              </StackPanel>
+            </StackPanel>
+
+            <Separator Margin="0,8"/>
 
             <TextBlock Text="WebUntis-Stundenplan-Abgleich" FontSize="16" FontWeight="SemiBold"/>
             <TextBlock FontSize="12" Opacity="0.6" TextWrapping="Wrap"

LehrerApp.Desktop/Views/Settings/SettingsView.axaml.cs

@@ -4,8 +4,10 @@ using Avalonia.Platform.Storage;
 using LehrerApp.Core.Interfaces;
 using LehrerApp.Desktop.Services;
 using LehrerApp.Desktop.ViewModels;
+using LehrerApp.Desktop.ViewModels.Groups;
 using LehrerApp.Desktop.ViewModels.Planning;
 using LehrerApp.Desktop.ViewModels.Settings;
+using LehrerApp.Desktop.Views.Groups;
 using LehrerApp.Desktop.Views.Planning;
 using LehrerApp.Desktop.Views.Shared;
 using Microsoft.Extensions.DependencyInjection;
@@ -31,6 +33,7 @@ public partial class SettingsView : UserControl
             vm.OnConfirmRecoveryRestore = ShowRecoveryRestoreConfirmDialog;
             vm.OnThemeChanged = App.ApplyTheme;
             vm.OnReviewUntisMapping = ShowUntisMappingReviewDialog;
+            vm.OnPickHomeroomClass = PickHomeroomClassAsync;
             _ = vm.LoadSchoolLocationCommand.ExecuteAsync(null);
         }
     }
@@ -51,6 +54,20 @@ public partial class SettingsView : UserControl
         await dialog.ShowDialog<bool>(owner);
     }
 
+    private async Task<(int UntisId, string Name)?> PickHomeroomClassAsync()
+    {
+        var owner = TopLevel.GetTopLevel(this) as Window;
+        if (owner is null) return null;
+
+        var untis = App.Services.GetRequiredService<WebUntisIntegrationService>();
+        var selectionVm = new WebUntisClassSelectionViewModel(untis);
+        var selection = new WebUntisClassSelectionDialog { DataContext = selectionVm };
+        await selectionVm.InitializeAsync();
+        if (!await selection.ShowDialog<bool>(owner) || selectionVm.SelectedClass is null) return null;
+
+        return (selectionVm.SelectedClass.UntisId, selectionVm.SelectedClass.Name);
+    }
+
     private async Task<bool> SaveRecoveryFile(string content)
     {
         var topLevel = TopLevel.GetTopLevel(this);

LehrerApp.Desktop/Views/Students/DocumentationDialog.axaml

@@ -233,6 +233,9 @@
 
         <CheckBox Content="Vertraulich" IsChecked="{Binding IsConfidential}"
                   ToolTip.Tip="Blendet den Inhalt in der Übersicht standardmäßig aus; erst nach Klick auf 'Anzeigen' sichtbar."/>
+
+        <CheckBox Content="Nicht mit WebUntis abgleichen" IsChecked="{Binding ExcludeFromWebUntisSync}"
+                  ToolTip.Tip="Erscheint dann nicht als Vorschlag zum Nacherfassen im WebUntis-Klassenbuch-Abgleich (Dashboard)."/>
       </StackPanel>
     </ScrollViewer>
 

LehrerApp.Desktop/Views/Students/WebUntisDocumentationComparisonDialog.axaml

@@ -0,0 +1,88 @@
+<Window xmlns="https://github.com/avaloniaui"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        xmlns:vm="clr-namespace:LehrerApp.Desktop.ViewModels.Students"
+        x:Class="LehrerApp.Desktop.Views.Students.WebUntisDocumentationComparisonDialog"
+        x:DataType="vm:WebUntisDocumentationComparisonViewModel"
+        Title="Klassenbucheinträge mit WebUntis abgleichen" Width="1150" Height="720"
+        MinWidth="900" MinHeight="500" WindowStartupLocation="CenterOwner">
+  <Grid RowDefinitions="Auto,Auto,Auto,2*,Auto,Auto,1*,Auto" Margin="24" RowSpacing="8">
+    <StackPanel Grid.Row="0" Spacing="4">
+      <TextBlock Text="Klassenbucheinträge mit WebUntis abgleichen" Classes="dialogtitle"/>
+      <TextBlock TextWrapping="Wrap" FontSize="12" Opacity="0.65"
+                 Text="Nur eigene WebUntis-Einträge (Benutzer = eigener Login). Zeilen ohne automatische Zuordnung bitte manuell einem/einer Schüler*in zuweisen. Bereits lokal vorhandene Einträge sind gesperrt."/>
+    </StackPanel>
+    <StackPanel Grid.Row="1" Orientation="Horizontal" Spacing="8">
+      <DatePicker SelectedDate="{Binding StartDate}"/>
+      <TextBlock Text="bis" VerticalAlignment="Center"/>
+      <DatePicker SelectedDate="{Binding EndDate}"/>
+      <Button Content="Klassenbucheinträge laden" Command="{Binding LoadCommand}" IsEnabled="{Binding !Busy}"/>
+    </StackPanel>
+
+    <Grid Grid.Row="2" ColumnDefinitions="Auto,70,55,65,1.1*,1.1*,1*,1.3*,1.3*" ColumnSpacing="8" Margin="4,0">
+      <TextBlock Grid.Column="1" Text="Datum" FontSize="11" Opacity="0.6"/>
+      <TextBlock Grid.Column="2" Text="Klasse" FontSize="11" Opacity="0.6"/>
+      <TextBlock Grid.Column="3" Text="Fach" FontSize="11" Opacity="0.6"/>
+      <TextBlock Grid.Column="4" Text="Name (WebUntis)" FontSize="11" Opacity="0.6"/>
+      <TextBlock Grid.Column="5" Text="Zuordnung" FontSize="11" Opacity="0.6"/>
+      <TextBlock Grid.Column="6" Text="Kategorie" FontSize="11" Opacity="0.6"/>
+      <TextBlock Grid.Column="7" Text="Text" FontSize="11" Opacity="0.6"/>
+      <TextBlock Grid.Column="8" Text="Lokal am selben Tag" FontSize="11" Opacity="0.6"/>
+    </Grid>
+    <ScrollViewer Grid.Row="3">
+      <ItemsControl ItemsSource="{Binding Rows}">
+        <ItemsControl.ItemTemplate>
+          <DataTemplate x:DataType="vm:WebUntisDocumentationRow">
+            <Grid ColumnDefinitions="Auto,70,55,65,1.1*,1.1*,1*,1.3*,1.3*" ColumnSpacing="8" Margin="0,3">
+              <CheckBox Grid.Column="0" IsChecked="{Binding Selected}" IsEnabled="{Binding CanApply}"/>
+              <TextBlock Grid.Column="1" Text="{Binding DateLabel}" VerticalAlignment="Center"/>
+              <TextBlock Grid.Column="2" Text="{Binding ClassName}" VerticalAlignment="Center"/>
+              <TextBlock Grid.Column="3" Text="{Binding Subject}" VerticalAlignment="Center"/>
+              <TextBlock Grid.Column="4" Text="{Binding UntisStudentName}" VerticalAlignment="Center" TextWrapping="Wrap"/>
+              <ComboBox Grid.Column="5" ItemsSource="{Binding Candidates}" SelectedItem="{Binding AssignedStudent}"
+                        DisplayMemberBinding="{Binding FullName}" PlaceholderText="Schüler*in wählen…"
+                        HorizontalAlignment="Stretch"/>
+              <StackPanel Grid.Column="6" Spacing="0">
+                <TextBlock Text="{Binding CategoryName}" TextWrapping="Wrap"/>
+                <TextBlock Text="{Binding CategoryGroup}" FontSize="11" Opacity="0.6"/>
+              </StackPanel>
+              <TextBlock Grid.Column="7" Text="{Binding Text}" TextWrapping="Wrap" VerticalAlignment="Center"/>
+              <TextBlock Grid.Column="8" Text="{Binding ExistingLocalEntry}" TextWrapping="Wrap"
+                         Foreground="DarkOrange" VerticalAlignment="Center"
+                         IsVisible="{Binding ExistingLocalEntry, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"/>
+            </Grid>
+          </DataTemplate>
+        </ItemsControl.ItemTemplate>
+      </ItemsControl>
+    </ScrollViewer>
+    <Grid Grid.Row="4" ColumnDefinitions="*,Auto" ColumnSpacing="8">
+      <TextBlock Grid.Column="0" Text="{Binding Status}" FontSize="12" TextWrapping="Wrap" VerticalAlignment="Center"/>
+      <Button Grid.Column="1" Content="Markierte übernehmen" Command="{Binding ApplyCommand}" IsEnabled="{Binding !Busy}"/>
+    </Grid>
+
+    <StackPanel Grid.Row="5" Spacing="2">
+      <TextBlock Text="Lokale Einträge im Zeitraum ohne WebUntis-Gegenstück" FontWeight="SemiBold" FontSize="13"/>
+      <TextBlock FontSize="12" Opacity="0.65" TextWrapping="Wrap"
+                 Text="Kein Schreibzugriff auf WebUntis — Text zum manuellen Nacherfassen in die Zwischenablage kopieren."/>
+    </StackPanel>
+    <ScrollViewer Grid.Row="6">
+      <ItemsControl ItemsSource="{Binding LocalOnlyRows}">
+        <ItemsControl.ItemTemplate>
+          <DataTemplate x:DataType="vm:LocalOnlyDocumentationRow">
+            <Grid ColumnDefinitions="80,1.2*,1.5*,2.5*,Auto" ColumnSpacing="8" Margin="0,3">
+              <TextBlock Grid.Column="0" Text="{Binding DateLabel}" VerticalAlignment="Center"/>
+              <TextBlock Grid.Column="1" Text="{Binding StudentName}" VerticalAlignment="Center" TextWrapping="Wrap"/>
+              <TextBlock Grid.Column="2" Text="{Binding GroupName}" VerticalAlignment="Center" TextWrapping="Wrap"/>
+              <StackPanel Grid.Column="3">
+                <TextBlock Text="{Binding Title}" FontWeight="SemiBold"/>
+                <TextBlock Text="{Binding Content}" TextWrapping="Wrap" FontSize="12" Opacity="0.8"/>
+              </StackPanel>
+              <Button Grid.Column="4" Content="In Zwischenablage" Click="OnCopyToClipboardClick"/>
+            </Grid>
+          </DataTemplate>
+        </ItemsControl.ItemTemplate>
+      </ItemsControl>
+    </ScrollViewer>
+
+    <Button Grid.Row="7" Content="Schließen" Click="OnClose" HorizontalAlignment="Right"/>
+  </Grid>
+</Window>

LehrerApp.Desktop/Views/Students/WebUntisDocumentationComparisonDialog.axaml.cs

@@ -0,0 +1,24 @@
+using Avalonia.Controls;
+using Avalonia.Input.Platform;
+using Avalonia.Interactivity;
+using LehrerApp.Desktop.Services;
+using LehrerApp.Desktop.ViewModels.Students;
+using Microsoft.Extensions.DependencyInjection;
+
+namespace LehrerApp.Desktop.Views.Students;
+
+public partial class WebUntisDocumentationComparisonDialog : Window
+{
+    public WebUntisDocumentationComparisonDialog() => InitializeComponent();
+
+    private void OnClose(object? sender, RoutedEventArgs e) => Close();
+
+    private async void OnCopyToClipboardClick(object? sender, RoutedEventArgs e)
+    {
+        if (sender is not Button { DataContext: LocalOnlyDocumentationRow row }) return;
+        var clipboard = TopLevel.GetTopLevel(this)?.Clipboard;
+        if (clipboard is null) return;
+        await clipboard.SetTextAsync(row.ClipboardText);
+        App.Services.GetRequiredService<NotificationService>().ShowSuccess("In die Zwischenablage kopiert.");
+    }
+}

LehrerApp.Sync.Tests/SyncEngineTests.cs

@@ -229,6 +229,95 @@ public sealed class SyncEngineTests
         Assert.Equal(0, temp.Queue.PendingCount());
     }
 
+    [Fact]
+    public async Task SyncNowAsync_MehrAlsEinPushBatch_LeertQueueInEinemSync()
+    {
+        using var temp = new TempEventQueue();
+        for (var i = 0; i < SyncProtocol.PushBatchSize + 5; i++)
+            temp.Queue.Enqueue("this-device", DeviceType.Desktop,
+                "Lesson", Guid.NewGuid().ToString(), "Save", $"payload-{i}");
+
+        var pushedBatchSizes = new List<int>();
+        long serverSeq = 0;
+        var handler = new FakeHttpMessageHandler(req =>
+        {
+            if (req.RequestUri!.AbsolutePath == "/api/sync/push")
+            {
+                var events = req.Content!.ReadFromJsonAsync<List<SyncEvent>>().GetAwaiter().GetResult()!;
+                pushedBatchSizes.Add(events.Count);
+                var assigned = events.ToDictionary(e => e.EventId, _ => ++serverSeq);
+                return new HttpResponseMessage(HttpStatusCode.OK)
+                {
+                    Content = JsonContent.Create(new PushResponse
+                    { ServerSequenceNr = serverSeq, AssignedServerSeqs = assigned }),
+                };
+            }
+            return new HttpResponseMessage(HttpStatusCode.OK)
+            { Content = JsonContent.Create(new PullResponse()) };
+        });
+        var engine = MakeEngine(temp, handler);
+
+        var result = await engine.SyncNowAsync();
+
+        Assert.True(result.Success);
+        Assert.Equal(SyncProtocol.PushBatchSize + 5, result.EventsPushed);
+        Assert.Equal([SyncProtocol.PushBatchSize, 5], pushedBatchSizes);
+        Assert.Equal(0, temp.Queue.PendingCount());
+    }
+
+    [Fact]
+    public async Task SyncNowAsync_VollerPullBatch_LaedtFolgebatchImSelbenSync()
+    {
+        using var temp = new TempEventQueue();
+        using var db = NewInMemoryContext();
+        var allEvents = Enumerable.Range(1, SyncProtocol.PullBatchSize + 3)
+            .Select(sequence =>
+            {
+                var student = new Student { FirstName = $"Vorname-{sequence}", LastName = "Beispiel" };
+                return new SyncEvent
+                {
+                    DeviceId = "other-device", DeviceType = DeviceType.Desktop,
+                    EntityType = nameof(Student), EntityId = student.Id.ToString(),
+                    Operation = "Save", Payload = SyncCrypto.EncryptObject(student, Key),
+                    SequenceNr = sequence,
+                };
+            }).ToList();
+        var pullRequests = 0;
+        var handler = new FakeHttpMessageHandler(req =>
+        {
+            if (req.RequestUri!.AbsolutePath == "/api/sync/pull")
+            {
+                pullRequests++;
+                var since = long.Parse(req.RequestUri.Query.TrimStart('?').Split('&')
+                    .Select(part => part.Split('=')).Single(part => part[0] == "since")[1]);
+                var events = allEvents.Where(e => e.SequenceNr > since)
+                    .Take(SyncProtocol.PullBatchSize).ToList();
+                return new HttpResponseMessage(HttpStatusCode.OK)
+                {
+                    Content = JsonContent.Create(new PullResponse
+                    {
+                        Events = events,
+                        ServerSequenceNr = events.Count == 0 ? since : events[^1].SequenceNr,
+                    }),
+                };
+            }
+            return new HttpResponseMessage(HttpStatusCode.OK)
+            { Content = JsonContent.Create(new PushResponse()) };
+        });
+        var engine = MakeEngine(temp, handler, new EventApplier(db, Key, versions: temp.Queue));
+        var dataChangedCount = 0;
+        engine.DataChanged += () => dataChangedCount++;
+
+        var result = await engine.SyncNowAsync();
+
+        Assert.True(result.Success);
+        Assert.Equal(SyncProtocol.PullBatchSize + 3, result.EventsPulled);
+        Assert.Equal(2, pullRequests);
+        Assert.Equal(SyncProtocol.PullBatchSize + 3, db.Students.Count());
+        Assert.Equal(SyncProtocol.PullBatchSize + 3, temp.Queue.GetLastServerSeq());
+        Assert.Equal(1, dataChangedCount);
+    }
+
     [Fact]
     public async Task PushAsync_SetztBasedOnServerSeqAusLokalerVersionsverfolgung()
     {

LehrerApp.Sync/EventQueue.cs

@@ -49,8 +49,14 @@ public class EventQueue : IDisposable
         return evt;
     }
 
-    public List<SyncEvent> GetPending(int max = 200) =>
+    public List<SyncEvent> GetPending(int max = SyncProtocol.PushBatchSize,
-        _queue.Find(Query.All(nameof(SyncEvent.SequenceNr))).Take(max).ToList();
+        IReadOnlySet<Guid>? excludedEventIds = null)
+    {
+        var pending = _queue.Find(Query.All(nameof(SyncEvent.SequenceNr))).AsEnumerable();
+        if (excludedEventIds is not null)
+            pending = pending.Where(e => !excludedEventIds.Contains(e.EventId));
+        return pending.Take(max).ToList();
+    }
     public int PendingCount() => _queue.Count();
     public void Acknowledge(IEnumerable<Guid> ids) { foreach (var id in ids) _queue.Delete(id); }
     public long GetLastServerSeq() => _meta.FindById("serverSeq")?.Value ?? 0;

LehrerApp.Sync/SyncEngine.cs

@@ -86,14 +86,37 @@ public class SyncEngine : IDisposable
 
     private async Task<SyncResult> RunSyncAsync(bool isAutomatic)
     {
+        var pulledDataChanged = false;
         SetState(SyncState.Syncing);
         _logger?.Info($"Sync: Start ({(isAutomatic ? "automatisch" : "manuell")}), Gerät={_config.DeviceId}, " +
                       $"{_queue.PendingCount()} lokal ausstehend");
         try
         {
-            var (pushed, pushConflicts) = await PushAsync();
+            var pushed = 0;
+            var pushConflicts = 0;
+            var deferredPushEvents = new HashSet<Guid>();
+            PushBatchResult pushBatch;
+            do
+            {
+                pushBatch = await PushAsync(deferredPushEvents);
+                pushed += pushBatch.Pushed;
+                pushConflicts += pushBatch.Conflicts;
+                deferredPushEvents.UnionWith(pushBatch.DeferredEventIds);
+            } while (pushBatch.SourceEventCount == SyncProtocol.PushBatchSize);
+
             await _attachments.UploadPendingAsync(_queue);
-            var (pulled, conflicts) = await PullAsync();
+
+            var pulled = 0;
+            var conflicts = 0;
+            PullBatchResult pullBatch;
+            do
+            {
+                pullBatch = await PullAsync();
+                pulled += pullBatch.Pulled;
+                conflicts += pullBatch.Conflicts;
+                pulledDataChanged |= pullBatch.Pulled > 0;
+            } while (pullBatch.Pulled == SyncProtocol.PullBatchSize);
+
             _queue.SetLastSyncAt(DateTime.UtcNow);
             SetState(SyncState.Idle);
             _logger?.Info($"Sync: Fertig - {pushed} gepusht ({pushConflicts} Push-Konflikte), " +
@@ -121,12 +144,19 @@ public class SyncEngine : IDisposable
             SetState(SyncState.Error, ex.Message);
             return new() { Reason = ex.Message };
         }
+        finally
+        {
+            // Auch wenn ein späterer Batch fehlschlägt, wurden frühere Batches bereits dauerhaft
+            // angewendet. Die Oberfläche muss diesen erfolgreich übernommenen Zwischenstand dann
+            // trotzdem neu laden; bei einem erfolgreichen Drain feuert der Hook genau einmal.
+            if (pulledDataChanged) DataChanged?.Invoke();
+        }
     }
 
-    private async Task<(int Pushed, int Conflicts)> PushAsync()
+    private async Task<PushBatchResult> PushAsync(IReadOnlySet<Guid> excludedEventIds)
     {
-        var pending = DeduplicatePending();
+        var pending = DeduplicatePending(excludedEventIds, out var sourceEventCount);
-        if (pending.Count == 0) return (0, 0);
+        if (pending.Count == 0) return new(0, 0, sourceEventCount, []);
         // BasedOnServerSeq erst unmittelbar vor dem Senden setzen (nicht beim Enqueue) - zwischen
         // Enqueue und Push kann ein Pull den lokal bekannten Stand dieser Entität aktualisiert
         // haben (siehe EventApplier.ApplyAsync).
@@ -139,7 +169,11 @@ public class SyncEngine : IDisposable
         using var resp = await _http.SendAsync(request);
         await SyncProtocol.EnsureCompatibleSuccessAsync(resp);
         var result = await resp.Content.ReadFromJsonAsync<PushResponse>();
-        if (result is null) { _logger?.Warn("Sync: Push - leere Server-Antwort."); return (0, 0); }
+        if (result is null)
+        {
+            _logger?.Warn("Sync: Push - leere Server-Antwort.");
+            return new(0, 0, sourceEventCount, pending.Select(e => e.EventId).ToList());
+        }
         _queue.Acknowledge(pending
             .Where(e => !result.ConflictingEventIds.Contains(e.EventId))
             .Select(e => e.EventId));
@@ -161,8 +195,8 @@ public class SyncEngine : IDisposable
                       $"{result.ConflictingEventIds.Count} abgelehnt (Konflikt).");
         if (result.ConflictingEventIds.Count > 0)
             await HandleRejectedAsync(pending.Where(e => result.ConflictingEventIds.Contains(e.EventId)));
-        return (pending.Count - result.ConflictingEventIds.Count,
+        return new(pending.Count - result.ConflictingEventIds.Count,
-                result.ConflictingEventIds.Count);
+            result.ConflictingEventIds.Count, sourceEventCount, result.ConflictingEventIds);
     }
 
     // Payload ist immer ein vollständiges Entitäts-Snapshot (nie ein Delta, siehe
@@ -171,9 +205,11 @@ public class SyncEngine : IDisposable
     // exakte BasedOnServerSeq-Prüfung: ohne Dedup könnten zwei Ereignisse derselben Entität im
     // selben Batch mit demselben (veralteten) BasedOnServerSeq ankommen und sich gegenseitig ins
     // Aus laufen.
-    private List<SyncEvent> DeduplicatePending()
+    private List<SyncEvent> DeduplicatePending(IReadOnlySet<Guid> excludedEventIds,
+        out int sourceEventCount)
     {
-        var pending = _queue.GetPending();
+        var pending = _queue.GetPending(SyncProtocol.PushBatchSize, excludedEventIds);
+        sourceEventCount = pending.Count;
         if (pending.Count == 0) return pending;
         var latest = pending
             .GroupBy(e => (e.EntityType, e.EntityId))
@@ -259,7 +295,7 @@ public class SyncEngine : IDisposable
         }
     }
 
-    private async Task<(int Pulled, int Conflicts)> PullAsync()
+    private async Task<PullBatchResult> PullAsync()
     {
         var since = _queue.GetLastServerSeq();
         _logger?.Info($"Sync: Pull - frage Server nach Ereignissen seit ServerSequenceNr={since}.");
@@ -271,7 +307,7 @@ public class SyncEngine : IDisposable
         if (resp is null || resp.Events.Count == 0)
         {
             _logger?.Info("Sync: Pull - keine neuen Ereignisse vom Server.");
-            return (0, 0);
+            return new(0, 0);
         }
         _logger?.Info($"Sync: Pull - {resp.Events.Count} Ereignis(se) vom Server erhalten: " +
                       string.Join(", ", resp.Events.Select(e => $"{e.EntityType}/{e.Operation}")));
@@ -287,10 +323,13 @@ public class SyncEngine : IDisposable
             if (c.Resolution == "RemoteWon") await _applier.ApplyAsync(evt);
         }
         _queue.SetLastServerSeq(resp.ServerSequenceNr);
-        DataChanged?.Invoke();
+        return new(resp.Events.Count, conflicts);
-        return (resp.Events.Count, conflicts);
     }
 
+    private readonly record struct PushBatchResult(int Pushed, int Conflicts,
+        int SourceEventCount, IReadOnlyCollection<Guid> DeferredEventIds);
+    private readonly record struct PullBatchResult(int Pulled, int Conflicts);
+
     private void SetState(SyncState state, string? error = null)
     {
         Status = new SyncStatus

LehrerApp.Sync/SyncProtocol.cs

@@ -14,6 +14,8 @@ public static class SyncProtocol
 {
     public const string CurrentVersion = "1";
     public const string VersionHeaderName = "X-LehrerApp-Sync-Version";
+    public const int PushBatchSize = 200;
+    public const int PullBatchSize = 500;
 
     public static HttpRequestMessage CreateRequest(HttpMethod method, string requestUri)
     {

LehrerApp.Tests/ExamPriorityServiceTests.cs

@@ -0,0 +1,102 @@
+using LehrerApp.Core.Models;
+using LehrerApp.Core.Services;
+using Xunit;
+
+namespace LehrerApp.Tests;
+
+public class ExamPriorityServiceTests
+{
+    private static Exam MakeExam(ExamStatus status, DateOnly date) => new()
+    {
+        GroupId = Guid.NewGuid(), Title = "Klausur", Status = status, Date = date,
+    };
+
+    [Fact]
+    public void Evaluate_UnbearbeiteteKorrekturSteigtMitAlter()
+    {
+        var today = new DateOnly(2026, 8, 29);
+        var exam = MakeExam(ExamStatus.Conducted, today.AddDays(-10));
+
+        var result = ExamPriorityService.Evaluate(exam, expected: 20, evaluated: 0, today);
+
+        Assert.Equal(ExamListStatus.AwaitingCorrection, result.Status);
+    }
+
+    [Fact]
+    public void Evaluate_UnbearbeiteteKorrekturIstDringenderAlsLaufendeKorrektur()
+    {
+        var today = new DateOnly(2026, 8, 29);
+        var untouched = MakeExam(ExamStatus.Conducted, today.AddDays(-10));
+        var inProgress = MakeExam(ExamStatus.Conducted, today.AddDays(-10));
+
+        var untouchedResult = ExamPriorityService.Evaluate(untouched, expected: 20, evaluated: 0, today);
+        var progressResult  = ExamPriorityService.Evaluate(inProgress, expected: 20, evaluated: 10, today);
+
+        Assert.True(untouchedResult.Score > progressResult.Score);
+    }
+
+    [Fact]
+    public void Evaluate_LaufendeKorrekturIstDringenderAlsGeplanteKlausur()
+    {
+        var today = new DateOnly(2026, 8, 29);
+        var inProgress = MakeExam(ExamStatus.Conducted, today.AddDays(-2));
+        var planned     = MakeExam(ExamStatus.Planned, today.AddDays(1));
+
+        var progressResult = ExamPriorityService.Evaluate(inProgress, expected: 20, evaluated: 10, today);
+        var plannedResult  = ExamPriorityService.Evaluate(planned, expected: 20, evaluated: 0, today);
+
+        Assert.True(progressResult.Score > plannedResult.Score);
+    }
+
+    [Fact]
+    public void Evaluate_HängengebliebeneKorrekturFälltAusDerDringlichenZone()
+    {
+        var today = new DateOnly(2026, 8, 29);
+        var stuck = MakeExam(ExamStatus.Conducted, today.AddDays(-(ExamPriorityService.StuckAfterDays + 5)));
+        var fresh = MakeExam(ExamStatus.Conducted, today.AddDays(-2));
+
+        // Ein einzelner nie nachschreibender Schüler: 19 von 20 erledigt, seit Wochen unverändert.
+        var stuckResult = ExamPriorityService.Evaluate(stuck, expected: 20, evaluated: 19, today);
+        var freshResult = ExamPriorityService.Evaluate(fresh, expected: 20, evaluated: 10, today);
+
+        Assert.Equal(ExamListStatus.CorrectionStuck, stuckResult.Status);
+        Assert.True(stuckResult.Score < freshResult.Score);
+    }
+
+    [Fact]
+    public void Evaluate_VollständigBewertetGiltAlsBereitZurRückgabe()
+    {
+        var today = new DateOnly(2026, 8, 29);
+        var exam = MakeExam(ExamStatus.Conducted, today.AddDays(-5));
+
+        var result = ExamPriorityService.Evaluate(exam, expected: 20, evaluated: 20, today);
+
+        Assert.Equal(ExamListStatus.AwaitingReturn, result.Status);
+    }
+
+    [Fact]
+    public void Evaluate_ZurückgegebenIstAmWenigstenDringlich()
+    {
+        var today = new DateOnly(2026, 8, 29);
+        var returned = MakeExam(ExamStatus.Returned, today.AddDays(-30));
+        var planned   = MakeExam(ExamStatus.Planned, today.AddDays(60));
+
+        var returnedResult = ExamPriorityService.Evaluate(returned, expected: 20, evaluated: 20, today);
+        var plannedResult  = ExamPriorityService.Evaluate(planned, expected: 20, evaluated: 0, today);
+
+        Assert.True(returnedResult.Score < plannedResult.Score);
+    }
+
+    [Fact]
+    public void Count_AbwesenderSchülerGiltAlsErledigt()
+    {
+        var exam = MakeExam(ExamStatus.Conducted, new DateOnly(2026, 8, 20));
+        var membership = new GroupMembership { GroupId = exam.GroupId, StudentId = Guid.NewGuid() };
+        var results = new List<ExamResult> { new() { ExamId = exam.Id, StudentId = membership.StudentId, Absent = true } };
+
+        var (expected, evaluated) = ExamCorrectionCounter.Count(exam, [membership], results);
+
+        Assert.Equal(1, expected);
+        Assert.Equal(1, evaluated);
+    }
+}

LehrerApp.Tests/GroupRolloverServiceTests.cs

@@ -14,7 +14,7 @@ public sealed class GroupRolloverServiceTests
         {
             Name = "8a", SchoolYear = "2025/26", GradeLevel = 8,
             Type = GroupType.Class, SubjectId = Guid.NewGuid(), GradingSystem = GradingSystem.Grades1To6,
-            HoursPerWeek = 4, IsOwnClass = true, IsDifferentiated = true,
+            HoursPerWeek = 4, IsOwnClass = true, IsDifferentiated = true, WebUntisLessonId = 38262,
         };
         var oldMembership = new GroupMembership
         {
@@ -38,6 +38,7 @@ public sealed class GroupRolloverServiceTests
         Assert.Equal(source.HoursPerWeek, target.HoursPerWeek);
         Assert.True(target.IsOwnClass);
         Assert.True(target.IsDifferentiated);
+        Assert.Null(target.WebUntisLessonId);
         Assert.False(source.IsActive);
 
         var copied = Assert.Single(memberships.GetByGroup(target.Id));

LehrerApp.WebUntis.Tests/LehrerApp.WebUntis.Tests.csproj

@@ -0,0 +1,18 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <TargetFramework>net10.0</TargetFramework>
+    <IsPackable>false</IsPackable>
+    <IsTestProject>true</IsTestProject>
+  </PropertyGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\LehrerApp.WebUntis\LehrerApp.WebUntis.csproj" />
+  </ItemGroup>
+  <ItemGroup>
+    <PackageReference Include="Microsoft.NET.Test.Sdk" />
+    <PackageReference Include="xunit" />
+    <PackageReference Include="xunit.runner.visualstudio">
+      <PrivateAssets>all</PrivateAssets>
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+    </PackageReference>
+  </ItemGroup>
+</Project>

LehrerApp.WebUntis.Tests/WebUntisClassRegisterEventReportParserTests.cs

@@ -0,0 +1,45 @@
+using Xunit;
+using LehrerApp.WebUntis;
+
+namespace LehrerApp.WebUntis.Tests;
+
+public sealed class WebUntisClassRegisterEventReportParserTests
+{
+    [Fact]
+    public void Parse_UebernimmtAlleFelderUndZweistelligesJahr()
+    {
+        const string report = "\uFEFFKlasse\tDatum\tFach\tName\tBenutzer\tEintragskategorie\tKategoriegruppe\tText\r\n" +
+                              "10c\t24.08.26\tEng_G\tMuster Erika\ttownsend\tFehlende HA\tNegativ\tKeine Hausaufgaben gemacht.\r\n";
+
+        var entry = Assert.Single(WebUntisClassRegisterEventReportParser.Parse(report));
+
+        Assert.Equal("10c", entry.ClassName);
+        Assert.Equal(20260824, entry.Date);
+        Assert.Equal("Eng_G", entry.Subject);
+        Assert.Equal("Muster Erika", entry.StudentName);
+        Assert.Equal("townsend", entry.TeacherUsername);
+        Assert.Equal("Fehlende HA", entry.CategoryName);
+        Assert.Equal("Negativ", entry.CategoryGroup);
+        Assert.Equal("Keine Hausaufgaben gemacht.", entry.Text);
+    }
+
+    [Fact]
+    public void Parse_UeberspringtLeereZeilen()
+    {
+        const string report = "Klasse\tDatum\tFach\tName\tBenutzer\tEintragskategorie\tKategoriegruppe\tText\r\n" +
+                              "6a\t24.08.26\tNAT\tMuster Max\thedtrich\tMitarb. über Erwart.\tPositiv\tGut.\r\n" +
+                              "\t\t\t\t\t\t\t\r\n";
+
+        var entry = Assert.Single(WebUntisClassRegisterEventReportParser.Parse(report));
+        Assert.Equal("Muster Max", entry.StudentName);
+    }
+
+    [Fact]
+    public void Parse_LehntUngueltigesDatumAb()
+    {
+        const string report = "Klasse\tDatum\tFach\tName\tBenutzer\tEintragskategorie\tKategoriegruppe\tText\r\n" +
+                              "6a\tkein-datum\tNAT\tMuster Max\thedtrich\tMitarb. über Erwart.\tPositiv\tGut.\r\n";
+
+        Assert.Throws<InvalidDataException>(() => WebUntisClassRegisterEventReportParser.Parse(report));
+    }
+}

LehrerApp.WebUntis.Tests/WebUntisClientTests.cs

@@ -0,0 +1,357 @@
+using System.Net;
+using System.Diagnostics;
+using System.Text;
+using LehrerApp.WebUntis;
+using Xunit;
+
+namespace LehrerApp.WebUntis.Tests;
+
+public sealed class WebUntisClientTests
+{
+    [Fact]
+    public async Task AufeinanderfolgendeAbrufe_VerwendenDieselbeSessionBisZumDispose()
+    {
+        var latin1 = Encoding.Latin1.GetBytes(
+            "id\texternKey\tklasse.name\tlongName\tforeName\r\n" +
+            "1\t10\t7a\tMüller\tAda\r\n" +
+            "2\t20\t8b\tMeier\tBerta\r\n");
+        var handler = new QueueHandler(
+            Json("{\"jsonrpc\":\"2.0\",\"result\":{\"sessionId\":\"session-1\"}}"),
+            Json("{\"data\":{\"finished\":true,\"error\":false,\"reportParams\":\"foo=bar\"}}"),
+            new HttpResponseMessage(HttpStatusCode.OK)
+            {
+                Content = new ByteArrayContent(latin1),
+            },
+            Json("{\"jsonrpc\":\"2.0\",\"result\":[{\"id\":7,\"name\":\"2026/27\",\"startDate\":20260801,\"endDate\":20270731}]}"),
+            Json("{\"jsonrpc\":\"2.0\",\"result\":{}}"));
+        var client = CreateClient(handler);
+
+        var result = await client.GetStudentReportAsync("7a", CancellationToken.None);
+        var schoolYears = await client.GetSchoolYearsAsync(CancellationToken.None);
+
+        var student = Assert.Single(result.Students);
+        Assert.Equal("Ada Müller", student.DisplayName);
+        Assert.Equal("7a", result.ClassNameFilter);
+        Assert.Equal("2026/27", Assert.Single(schoolYears).Name);
+        Assert.Equal(4, handler.Requests.Count);
+        Assert.Contains("jsonrpc.do?school=meine-schule", handler.Requests[0].Uri);
+        Assert.Contains("\"method\":\"authenticate\"", handler.Requests[0].Body);
+        Assert.Contains("reports.do?name=Student", handler.Requests[1].Uri);
+        Assert.Contains("schoolname=\"_", handler.Requests[1].Cookie);
+        Assert.EndsWith("reports.do?foo=bar", handler.Requests[2].Uri);
+        Assert.Contains("\"method\":\"getSchoolyears\"", handler.Requests[3].Body);
+        Assert.Single(handler.Requests,
+            request => request.Body.Contains("\"method\":\"authenticate\""));
+
+        await client.DisposeAsync();
+
+        Assert.Equal(5, handler.Requests.Count);
+        Assert.Contains("\"method\":\"logout\"", handler.Requests[4].Body);
+    }
+
+    [Fact]
+    public async Task GetTimetableAsync_SendetElementUndZeitraumAlsSeparateAbfrage()
+    {
+        var handler = new QueueHandler(
+            Json("{\"result\":{\"sessionId\":\"s\"}}"),
+            Json("{\"result\":[{\"id\":99,\"date\":20260824,\"startTime\":800,\"endTime\":845," +
+                 "\"kl\":[{\"id\":4,\"name\":\"7a\"}],\"te\":[],\"su\":[],\"ro\":[]}]}"),
+            Json("{\"result\":{}}"));
+        var client = CreateClient(handler);
+
+        var periods = await client.GetTimetableAsync(UntisTimetableElementType.Teacher, 42,
+            20260824, 20260828, CancellationToken.None);
+
+        var period = Assert.Single(periods);
+        Assert.Equal(99, period.Id);
+        Assert.Equal("7a", Assert.Single(period.Classes).Name);
+        Assert.Contains("\"method\":\"getTimetable\"", handler.Requests[1].Body);
+        Assert.Contains("\"element\":{\"id\":42,\"type\":2}", handler.Requests[1].Body);
+        Assert.Contains("\"startDate\":20260824", handler.Requests[1].Body);
+
+        await client.DisposeAsync();
+    }
+
+    [Fact]
+    public async Task FehlendeKonfiguration_BrichtVorHttpRequestAb()
+    {
+        var handler = new QueueHandler();
+        var client = new WebUntisClient(new HttpClient(handler), new WebUntisOptions());
+
+        await Assert.ThrowsAsync<WebUntisConfigurationException>(
+            () => client.GetSchoolYearsAsync(CancellationToken.None));
+
+        Assert.Empty(handler.Requests);
+        await client.DisposeAsync();
+    }
+
+    [Fact]
+    public async Task Dispose_BegrenztEinenNichtAntwortendenLogout()
+    {
+        var handler = new HangingLogoutHandler();
+        var client = CreateClient(handler);
+        await client.GetSchoolYearsAsync(CancellationToken.None);
+
+        var elapsed = Stopwatch.StartNew();
+        await client.DisposeAsync();
+
+        Assert.True(elapsed.Elapsed < TimeSpan.FromSeconds(5));
+        Assert.True(handler.LogoutWasCancelled);
+    }
+
+    [Fact]
+    public async Task VollstaendigeLoginUrl_TrenntRegionalenServerUndSchulkennung()
+    {
+        var handler = new QueueHandler(
+            Json("{\"result\":{\"sessionId\":\"s\"}}"),
+            Json("{\"result\":[{\"id\":1,\"name\":\"2026/27\",\"startDate\":20260801,\"endDate\":20270731}]}"),
+            Json("{\"result\":{}}"));
+        var client = new WebUntisClient(new HttpClient(handler), new WebUntisOptions
+        {
+            School = "https://arche.webuntis.com/WebUntis/?school=bk-ostvest#/basic/login",
+            Username = "api-user",
+            Password = "secret",
+        });
+
+        await client.GetSchoolYearsAsync(CancellationToken.None);
+
+        Assert.StartsWith("https://arche.webuntis.com/WebUntis/jsonrpc.do", handler.Requests[0].Uri);
+        Assert.Contains("school=bk-ostvest", handler.Requests[0].Uri);
+        await client.DisposeAsync();
+    }
+
+    [Fact]
+    public async Task VollstaendigeServerUrl_WirdOhnePfadVerwendet()
+    {
+        var handler = new QueueHandler(
+            Json("{\"result\":{\"sessionId\":\"s\"}}"),
+            Json("{\"result\":[{\"id\":1,\"name\":\"2026/27\",\"startDate\":20260801,\"endDate\":20270731}]}"),
+            Json("{\"result\":{}}"));
+        var client = new WebUntisClient(new HttpClient(handler), new WebUntisOptions
+        {
+            School = "bk-ostvest",
+            Host = "https://arche.webuntis.com/WebUntis/?school=bk-ostvest#/basic/login",
+            Username = "api-user",
+            Password = "secret",
+        });
+
+        await client.GetSchoolYearsAsync(CancellationToken.None);
+
+        Assert.StartsWith("https://arche.webuntis.com/WebUntis/jsonrpc.do", handler.Requests[0].Uri);
+        Assert.Contains("school=bk-ostvest", handler.Requests[0].Uri);
+        await client.DisposeAsync();
+    }
+
+    [Fact]
+    public async Task Klassenbuch_WirdTypisiertAbgerufen()
+    {
+        var handler = new QueueHandler(
+            Json("{\"result\":{\"sessionId\":\"s\"}}"),
+            Json("{\"result\":[{\"studentid\":9001,\"surname\":\"Müller\",\"forname\":\"Ada\"," +
+                 "\"date\":20260902,\"subject\":\"MA\",\"categoryId\":3,\"reason\":\"Material\"," +
+                 "\"text\":\"Buch vergessen\"}]}"),
+            Json("{\"result\":[{\"id\":3,\"name\":\"Material\",\"longName\":\"Material vergessen\"," +
+                 "\"groupId\":2}]}"),
+            Json("{\"result\":[{\"id\":2,\"name\":\"Organisation\"}]}"),
+            Json("{\"result\":{}}"));
+        var client = CreateClient(handler);
+
+        var entries = await client.GetClassRegisterEntriesAsync(17, 20260801, 20270731,
+            CancellationToken.None);
+        var categories = await client.GetClassRegisterCategoriesAsync(CancellationToken.None);
+        var groups = await client.GetClassRegisterCategoryGroupsAsync(CancellationToken.None);
+
+        var entry = Assert.Single(entries);
+        Assert.Equal("Ada Müller", entry.DisplayName);
+        Assert.Equal("Buch vergessen", entry.Text);
+        Assert.Equal(3, Assert.Single(categories).Id);
+        Assert.Equal("Organisation", Assert.Single(groups).Name);
+        Assert.Contains("\"method\":\"getClassregEvents\"", handler.Requests[1].Body);
+        Assert.Contains("\"id\":17,\"type\":5", handler.Requests[1].Body);
+        Assert.Single(handler.Requests,
+            request => request.Body.Contains("\"method\":\"authenticate\""));
+
+        await client.DisposeAsync();
+        Assert.Contains("\"method\":\"logout\"", handler.Requests[^1].Body);
+    }
+
+    [Fact]
+    public async Task GetLessonAbsencesAsync_LoestTeacherIdAusDerEigenenSessionAufUndTypisiertDasErgebnis()
+    {
+        var csv = Encoding.UTF8.GetBytes(
+            "Schüler*innen\tDatum\tFehlstd.\tUnentsch. Fehlstd.\tFehlmin.\tUnentsch. Fehlmin.\tZeit\t" +
+            "Abwesenheitsgrund\tENr\tErledigt\tAbwesenheit zählt\r\n" +
+            "Erika Mustermann\t09.12.25\t1\t1\t45\t45\t09:40-10:25\tKrank\t(185120)\t09.12.25\ttrue\r\n");
+        var handler = new QueueHandler(
+            Json("{\"result\":{\"sessionId\":\"s\",\"personId\":89}}"),
+            Json("{\"data\":{\"finished\":true,\"error\":false," +
+                 "\"reportParams\":\"get=rpt1.tmp&name=AbsencePerLesson&format=csv\"}}"),
+            new HttpResponseMessage(HttpStatusCode.OK) { Content = new ByteArrayContent(csv) },
+            Json("{\"result\":{}}"));
+        var client = CreateClient(handler);
+
+        var absences = await client.GetLessonAbsencesAsync(38262, 20250811, 20260710, CancellationToken.None);
+
+        var absence = Assert.Single(absences);
+        Assert.Equal("Erika Mustermann", absence.StudentName);
+        Assert.Equal(20251209, absence.Date);
+        Assert.Equal(185120, absence.ExternKey);
+        Assert.True(absence.ExternKeyInParentheses);
+        Assert.Equal(940, absence.StartTime);
+        Assert.True(absence.Counts);
+        Assert.Contains("reports.do?name=AbsencePerLesson", handler.Requests[1].Uri);
+        Assert.Contains("lsid=38262", handler.Requests[1].Uri);
+        Assert.Contains("teacherId=89", handler.Requests[1].Uri);
+        Assert.Contains("rpt_sd=20250811", handler.Requests[1].Uri);
+        Assert.Contains("rpt_ed=20260710", handler.Requests[1].Uri);
+        Assert.EndsWith("reports.do?get=rpt1.tmp&name=AbsencePerLesson&format=csv", handler.Requests[2].Uri);
+
+        await client.DisposeAsync();
+    }
+
+    [Fact]
+    public async Task GetClassRegisterEventsReportAsync_BautDenBerichtsAbrufAufUndTypisiertDasErgebnis()
+    {
+        var csv = Encoding.UTF8.GetBytes(
+            "Klasse\tDatum\tFach\tName\tBenutzer\tEintragskategorie\tKategoriegruppe\tText\r\n" +
+            "6a\t24.08.26\tNAT\tMuster Max\thedtrich\tMitarb. über Erwart.\tPositiv\tArbeitet gut mit.\r\n");
+        var handler = new QueueHandler(
+            Json("{\"result\":{\"sessionId\":\"s\",\"personId\":89}}"),
+            Json("{\"data\":{\"finished\":true,\"error\":false," +
+                 "\"reportParams\":\"get=rpt2.tmp&name=ClassregEventPerStudent&format=csv\"}}"),
+            new HttpResponseMessage(HttpStatusCode.OK) { Content = new ByteArrayContent(csv) },
+            Json("{\"result\":{}}"));
+        var client = CreateClient(handler);
+
+        var report = await client.GetClassRegisterEventsReportAsync(20260824, 20260828, CancellationToken.None);
+
+        var entry = Assert.Single(report);
+        Assert.Equal("6a", entry.ClassName);
+        Assert.Equal(20260824, entry.Date);
+        Assert.Equal("NAT", entry.Subject);
+        Assert.Equal("Muster Max", entry.StudentName);
+        Assert.Equal("hedtrich", entry.TeacherUsername);
+        Assert.Equal("Mitarb. über Erwart.", entry.CategoryName);
+        Assert.Equal("Positiv", entry.CategoryGroup);
+        Assert.Equal("Arbeitet gut mit.", entry.Text);
+        Assert.Contains("reports.do?name=ClassregEventPerStudent", handler.Requests[1].Uri);
+        Assert.Contains("klasseOrStudentgroupId=-1", handler.Requests[1].Uri);
+        Assert.Contains("studentId=-1", handler.Requests[1].Uri);
+        Assert.Contains("rpt_sd=20260824", handler.Requests[1].Uri);
+        Assert.Contains("rpt_ed=20260828", handler.Requests[1].Uri);
+        Assert.EndsWith("reports.do?get=rpt2.tmp&name=ClassregEventPerStudent&format=csv", handler.Requests[2].Uri);
+
+        await client.DisposeAsync();
+    }
+
+    [Fact]
+    public async Task GetClassAbsencesAsync_BautDenBerichtsAbrufAufUndTypisiertDasErgebnis()
+    {
+        // Kopfzeile "Text" kommt zweimal vor (Spalte 3 leer, Spalte 12 die eigentliche Tagesnotiz) -
+        // deckt ab, dass die spätere Spalte beim Parsen die frühere überschreibt (siehe Parser-Kommentar).
+        var csv = Encoding.UTF8.GetBytes(
+            "Schüler*innen\tExterne Id\tText\tKlasse\tDatum\tWochentag\tFehlstd.\tFehlmin.\tLehrkraft\tFach\t" +
+            "Abwesenheitsgrund\tText\tENr\tErledigt\tAbwesenheit zählt\tEntschuldigungstext\tStundennr.\tStatus\tFehltage\r\n" +
+            "Muster Max\t12345\t\t6a\t24.08.26\tMo.\t1\t45\tHED\tChe\tAbsent\tKrank gemeldet\t555\t24.08.26\ttrue\t\t3\tnicht entsch.\t1\r\n");
+        var handler = new QueueHandler(
+            Json("{\"result\":{\"sessionId\":\"s\",\"personId\":89}}"),
+            Json("{\"data\":{\"finished\":true,\"error\":false," +
+                 "\"reportParams\":\"get=rpt3.tmp&name=AbsencePerStudent&format=csv\"}}"),
+            new HttpResponseMessage(HttpStatusCode.OK) { Content = new ByteArrayContent(csv) },
+            Json("{\"result\":{}}"));
+        var client = CreateClient(handler);
+
+        var entries = await client.GetClassAbsencesAsync("KL874", 20260824, 20260828, CancellationToken.None);
+
+        var entry = Assert.Single(entries);
+        Assert.Equal("Muster Max", entry.StudentName);
+        Assert.Equal(12345, entry.ExternKey);
+        Assert.Equal("6a", entry.ClassName);
+        Assert.Equal(20260824, entry.Date);
+        Assert.Equal(1, entry.AbsentPeriods);
+        Assert.Equal(45, entry.AbsentMinutes);
+        Assert.Equal("HED", entry.TeacherUsernames);
+        Assert.Equal("Che", entry.Subject);
+        Assert.Equal("Absent", entry.AbsenceReason);
+        Assert.Equal("Krank gemeldet", entry.Note);
+        Assert.Equal(555, entry.EntryId);
+        Assert.Equal("24.08.26", entry.HandledOn);
+        Assert.True(entry.Counts);
+        Assert.Null(entry.ExcuseNote);
+        Assert.Equal(3, entry.PeriodNumber);
+        Assert.Equal("nicht entsch.", entry.Status);
+        Assert.True(entry.CountsAsFullDay);
+        Assert.Contains("reports.do?name=AbsencePerStudent", handler.Requests[1].Uri);
+        Assert.Contains("klasseOrStudentgroupId=KL874", handler.Requests[1].Uri);
+        Assert.Contains("studentId=-1", handler.Requests[1].Uri);
+        Assert.Contains("rpt_sd=20260824", handler.Requests[1].Uri);
+        Assert.Contains("rpt_ed=20260828", handler.Requests[1].Uri);
+        Assert.EndsWith("reports.do?get=rpt3.tmp&name=AbsencePerStudent&format=csv", handler.Requests[2].Uri);
+
+        await client.DisposeAsync();
+    }
+
+    private static WebUntisClient CreateClient(HttpMessageHandler handler) => new(
+        new HttpClient(handler),
+        new WebUntisOptions
+        {
+            School = "meine-schule",
+            Host = "meine-schule.webuntis.com",
+            Username = "api-user",
+            Password = "secret",
+            Client = "tests",
+        });
+
+    private static HttpResponseMessage Json(string json) => new(HttpStatusCode.OK)
+    {
+        Content = new StringContent(json, Encoding.UTF8, "application/json"),
+    };
+
+    private sealed class QueueHandler(params HttpResponseMessage[] responses) : HttpMessageHandler
+    {
+        private readonly Queue<HttpResponseMessage> _responses = new(responses);
+        public List<CapturedRequest> Requests { get; } = [];
+
+        protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request,
+            CancellationToken cancellationToken)
+        {
+            Requests.Add(new CapturedRequest(
+                request.RequestUri?.ToString() ?? "",
+                request.Content is null ? "" : await request.Content.ReadAsStringAsync(cancellationToken),
+                string.Join("; ", request.Headers.TryGetValues("Cookie", out var cookies) ? cookies : [])));
+            return _responses.Count > 0
+                ? _responses.Dequeue()
+                : throw new InvalidOperationException("Keine Testantwort mehr vorhanden.");
+        }
+    }
+
+    private sealed class HangingLogoutHandler : HttpMessageHandler
+    {
+        public bool LogoutWasCancelled { get; private set; }
+
+        protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request,
+            CancellationToken cancellationToken)
+        {
+            var body = request.Content is null
+                ? ""
+                : await request.Content.ReadAsStringAsync(cancellationToken);
+            if (body.Contains("\"method\":\"authenticate\""))
+                return Json("{\"result\":{\"sessionId\":\"s\"}}");
+            if (body.Contains("\"method\":\"getSchoolyears\""))
+                return Json("{\"result\":[]}");
+
+            try
+            {
+                await Task.Delay(Timeout.InfiniteTimeSpan, cancellationToken);
+                throw new InvalidOperationException("Der simulierte Logout darf nicht regulär enden.");
+            }
+            catch (OperationCanceledException) when (cancellationToken.IsCancellationRequested)
+            {
+                LogoutWasCancelled = true;
+                throw;
+            }
+        }
+    }
+
+    private sealed record CapturedRequest(string Uri, string Body, string Cookie);
+}

LehrerApp.WebUntis.Tests/WebUntisLessonAbsenceParserTests.cs

@@ -0,0 +1,54 @@
+using Xunit;
+using LehrerApp.WebUntis;
+
+namespace LehrerApp.WebUntis.Tests;
+
+public sealed class WebUntisLessonAbsenceParserTests
+{
+    [Fact]
+    public void Parse_UebernimmtAlleFelderUndZweistelligesJahr()
+    {
+        const string report = "\uFEFFSchüler*innen\tDatum\tFehlstd.\tUnentsch. Fehlstd.\tFehlmin.\tUnentsch. Fehlmin.\tZeit\tAbwesenheitsgrund\tENr\tErledigt\tAbwesenheit zählt\r\n" +
+                              "Erika Mustermann\t09.12.25\t1\t1\t45\t45\t09:40-10:25\tKrank\t(185120)\t09.12.25\ttrue\r\n";
+
+        var absence = Assert.Single(WebUntisLessonAbsenceParser.Parse(report));
+
+        Assert.Equal("Erika Mustermann", absence.StudentName);
+        Assert.Equal(20251209, absence.Date);
+        Assert.Equal(1, absence.AbsentPeriods);
+        Assert.Equal(1, absence.UnexcusedAbsentPeriods);
+        Assert.Equal(45, absence.AbsentMinutes);
+        Assert.Equal(45, absence.UnexcusedAbsentMinutes);
+        Assert.Equal(940, absence.StartTime);
+        Assert.Equal(1025, absence.EndTime);
+        Assert.Equal("Krank", absence.Reason);
+        Assert.Equal(185120, absence.ExternKey);
+        Assert.True(absence.ExternKeyInParentheses);
+        Assert.Equal("09.12.25", absence.HandledOn);
+        Assert.True(absence.Counts);
+    }
+
+    [Fact]
+    public void Parse_AkzeptiertExterneSchuelerkennungOhneKlammern()
+    {
+        const string report = "Schüler*innen\tDatum\tFehlstd.\tUnentsch. Fehlstd.\tFehlmin.\tUnentsch. Fehlmin.\tZeit\tAbwesenheitsgrund\tENr\tErledigt\tAbwesenheit zählt\r\n" +
+                              "Max Muster\t27.01.26\t1\t0\t45\t0\t10:25-11:10\t\t178156\t\tfalse\r\n";
+
+        var absence = Assert.Single(WebUntisLessonAbsenceParser.Parse(report));
+
+        Assert.Equal(178156, absence.ExternKey);
+        Assert.False(absence.ExternKeyInParentheses);
+        Assert.Null(absence.Reason);
+        Assert.Null(absence.HandledOn);
+        Assert.False(absence.Counts);
+    }
+
+    [Fact]
+    public void Parse_LehntUngueltigesDatumAb()
+    {
+        const string report = "Schüler*innen\tDatum\tFehlstd.\tUnentsch. Fehlstd.\tFehlmin.\tUnentsch. Fehlmin.\tZeit\tAbwesenheitsgrund\tENr\tErledigt\tAbwesenheit zählt\r\n" +
+                              "Max Muster\tkein-datum\t1\t0\t45\t0\t10:25-11:10\t\t178156\t\tfalse\r\n";
+
+        Assert.Throws<InvalidDataException>(() => WebUntisLessonAbsenceParser.Parse(report));
+    }
+}

LehrerApp.WebUntis.Tests/WebUntisStudentReportParserTests.cs

@@ -0,0 +1,76 @@
+using Xunit;
+using LehrerApp.WebUntis;
+
+namespace LehrerApp.WebUntis.Tests;
+
+public sealed class WebUntisStudentReportParserTests
+{
+    [Fact]
+    public void Parse_UebernimmtAlleFelderUndDeutscheDatumswerte()
+    {
+        const string report = "\uFEFFid\texternKey\tklasse.name\tname\tlongName\tforeName\tgender\tbirthDate\tentryDate\texitDate\ttext\tmedicalReportDuty\tschulpflicht\tmajority\tadress.email\tadress.mobile\tadress.phone\tadress.city\tadress.postCode\tadress.street\tattribute.iL\r\n" +
+                              "17\t9001\t10a\tMUST\tMustermann\tErika\tw\t03.02.2010\t01.08.2021\t\t\"Zeile 1\nZeile 2\"\tja\tja\tnein\terika@example.org\t0151\t030\tBerlin\t10115\tTestweg 1\tIL-A\r\n";
+
+        var student = Assert.Single(WebUntisStudentReportParser.Parse(report));
+
+        Assert.Equal(17, student.UntisId);
+        Assert.Equal(9001, student.ExternKey);
+        Assert.Equal("10a", student.ClassName);
+        Assert.Equal("Erika Mustermann", student.DisplayName);
+        Assert.Equal(20100203, student.BirthDate);
+        Assert.Equal(20210801, student.EntryDate);
+        Assert.Null(student.ExitDate);
+        Assert.Equal("Zeile 1\nZeile 2", student.Text);
+        Assert.Equal("erika@example.org", student.Address.Email);
+        Assert.Equal("IL-A", student.AttributeIL);
+    }
+
+    [Fact]
+    public void Parse_BehandeltEscapteAnfuehrungszeichenUndLeereZeilen()
+    {
+        const string report = "id\texternKey\tklasse.name\tname\r\n" +
+                              "1\t2\t5b\t\"MUS\"\"T\"\r\n\t\t\t\r\n";
+
+        var student = Assert.Single(WebUntisStudentReportParser.Parse(report));
+
+        Assert.Equal("MUS\"T", student.Name);
+        Assert.Equal("MUS\"T", student.DisplayName);
+    }
+
+    [Fact]
+    public void Parse_AkzeptiertIsoDatumswerteOhneTrennzeichen()
+    {
+        const string report = "id\texternKey\tklasse.name\tbirthDate\tentryDate\texitDate\r\n" +
+                              "17\t9001\t10a\t20100203\t20210801\t20270731\r\n";
+
+        var student = Assert.Single(WebUntisStudentReportParser.Parse(report));
+
+        Assert.Equal(20100203, student.BirthDate);
+        Assert.Equal("20100203", student.BirthDateRaw);
+        Assert.Equal(20210801, student.EntryDate);
+        Assert.Equal(20270731, student.ExitDate);
+    }
+
+    [Fact]
+    public void Parse_ErlaubtFehlendenExternKey()
+    {
+        // Reale Schuldaten enthalten Schüler*innen ohne gepflegten externen Schlüssel (z.B. frisch
+        // angelegt) - das darf nicht den Abruf der gesamten Klassenliste zum Absturz bringen.
+        const string report = "id\texternKey\tklasse.name\r\n17\t\t10a\r\n";
+
+        var student = Assert.Single(WebUntisStudentReportParser.Parse(report));
+
+        Assert.Equal(17, student.UntisId);
+        Assert.Null(student.ExternKey);
+    }
+
+    [Fact]
+    public void Parse_LehntUngueltigePflichtIdAb()
+    {
+        const string report = "id\texternKey\tklasse.name\r\nkeine-zahl\t1\t5b\r\n";
+
+        var error = Assert.Throws<InvalidDataException>(() => WebUntisStudentReportParser.Parse(report));
+
+        Assert.Contains("id", error.Message);
+    }
+}

LehrerApp.WebUntis/LehrerApp.WebUntis.csproj

@@ -0,0 +1,5 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <TargetFramework>net10.0</TargetFramework>
+  </PropertyGroup>
+</Project>

LehrerApp.WebUntis/TabSeparatedTextReader.cs

@@ -0,0 +1,55 @@
+using System.Text;
+
+namespace LehrerApp.WebUntis;
+
+internal static class TabSeparatedTextReader
+{
+    public static List<List<string>> ParseRows(string content, char separator)
+    {
+        var rows = new List<List<string>>();
+        var row = new List<string>();
+        var field = new StringBuilder();
+        var inQuotes = false;
+
+        for (var index = 0; index < content.Length; index++)
+        {
+            var character = content[index];
+            if (character == '"')
+            {
+                if (inQuotes && index + 1 < content.Length && content[index + 1] == '"')
+                {
+                    field.Append('"');
+                    index++;
+                }
+                else
+                {
+                    inQuotes = !inQuotes;
+                }
+                continue;
+            }
+
+            if (!inQuotes && character == separator)
+            {
+                row.Add(field.ToString());
+                field.Clear();
+                continue;
+            }
+
+            if (!inQuotes && character == '\n')
+            {
+                row.Add(field.ToString());
+                rows.Add(row);
+                row = [];
+                field.Clear();
+                continue;
+            }
+
+            if (!inQuotes && character == '\r') continue;
+            field.Append(character);
+        }
+
+        row.Add(field.ToString());
+        if (row.Count > 1 || !string.IsNullOrWhiteSpace(row[0])) rows.Add(row);
+        return rows;
+    }
+}