Tagesflagge im Sitzplan, Leistungsüberblick mit Zielnoten-Rechner

- Mitarbeit: Tagesflagge (👑 Spitzentag / 😴 Schlaftag / ⚡ Schlechter Tag)
  je Schüler und Sitzung. Primär im Sitzplatz-Dialog (⇧1/2/3, ⇧X) mit
  Badge auf der Sitzplatz-Kachel; Fallback in der Schnelleingabe für
  Lerngruppen ohne Sitzplan.
- Noten: neuer Dialog "Überblick" in der Notenübersicht zeigt Klausuren,
  Mitarbeit- und sonstige Noten eines Schülers samt berechneter
  Zeugnisnote. Zielnoten-Rechner (ReportGradeTargetCalculator) beantwortet
  "was brauche ich noch für Note X", ein Was-wäre-wenn-Rechner simuliert
  eine zusätzliche Klausurnote. Bewerter-/Schülermodus per Umschalter im
  selben Fenster — Bewertermodus zeigt zusätzlich Kursdurchschnitt je
  Klausur und erlaubt das Bearbeiten von Mitarbeit-/Sonstige-Noten.
  Klausurverlauf als Balken-Sparkline wie die bestehende Notenentwicklung.

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

LehrerApp.Desktop/ViewModels/Groups/SeatingPlanViewModels.cs

@@ -547,11 +547,13 @@ public partial class SeatCellViewModel : ObservableObject
     [ObservableProperty] private double _lessonOpacity = 1.0;
     [ObservableProperty] private string _attendanceBadge = "";
     [ObservableProperty] private string _homeworkBadge = "";
+    [ObservableProperty] private string _dayHighlightBadge = "";
     [ObservableProperty] private int _raisedHandCount;
     [ObservableProperty] private int _calledOnCount;
     public ObservableCollection<SituationTagChoice> SituationTags { get; } = [];
     public bool HasAttendanceBadge => AttendanceBadge.Length > 0;
     public bool HasHomeworkBadge => HomeworkBadge.Length > 0;
+    public bool HasDayHighlightBadge => DayHighlightBadge.Length > 0;
     public bool ShowLessonOverview => IsOccupied && !CanEdit;
     [ObservableProperty] private bool _canRecordLesson;
     public bool IsOccupied => SelectedOption.StudentId.HasValue;
@@ -644,6 +646,7 @@ public partial class SeatCellViewModel : ObservableObject
         var attendance = entry?.Attendance;
         AttendanceBadge = attendance is null ? "" : AttendanceDisplay.ShortLabel(attendance);
         HomeworkBadge = entry is null ? "" : HomeworkDisplay.Symbol(HomeworkDisplay.Effective(entry));
+        DayHighlightBadge = DayHighlightDisplay.Symbol(entry?.DayHighlight);
         RaisedHandCount = entry?.RaisedHandCount ?? 0;
         CalledOnCount = entry?.CalledOnCount ?? 0;
         LessonOpacity = attendance is not null and not AttendanceStatus.Present
@@ -652,6 +655,7 @@ public partial class SeatCellViewModel : ObservableObject
         foreach (var choice in SituationTags) choice.IsSelected = selected.Contains(choice.Text);
         OnPropertyChanged(nameof(HasAttendanceBadge));
         OnPropertyChanged(nameof(HasHomeworkBadge));
+        OnPropertyChanged(nameof(HasDayHighlightBadge));
     }
 }
 
@@ -677,6 +681,7 @@ public partial class SeatAssessmentViewModel : ObservableObject
     [ObservableProperty] private int _selectedAspectIndex;
     [ObservableProperty] private string _attendanceLabel = "Noch nicht kontrolliert";
     [ObservableProperty] private string _homeworkLabel = "Keine Hausaufgabe aufgegeben";
+    [ObservableProperty] private string _dayHighlightLabel = "Keine Markierung";
 
     public string StudentName { get; }
     public string SessionDisplay { get; }
@@ -687,6 +692,7 @@ public partial class SeatAssessmentViewModel : ObservableObject
     public ObservableCollection<SeatAssessmentAspectRow> AspectRows { get; } = [];
     public ObservableCollection<SeatAttendanceChoice> AttendanceChoices { get; } = [];
     public ObservableCollection<SeatHomeworkChoice> HomeworkChoices { get; } = [];
+    public ObservableCollection<SeatDayHighlightChoice> DayHighlightChoices { get; } = [];
 
     public SeatAssessmentViewModel(IParticipationSessionRepository sessions,
         IParticipationRepository entries, IParticipationAspectRepository aspects,
@@ -729,6 +735,7 @@ public partial class SeatAssessmentViewModel : ObservableObject
 
         BuildAttendanceChoices();
         BuildHomeworkChoices();
+        BuildDayHighlightChoices();
         RefreshStatusChoices();
         SelectAspect(0);
     }
@@ -761,6 +768,17 @@ public partial class SeatAssessmentViewModel : ObservableObject
         HomeworkChoices.Add(new("·", "Keine aufgegeben", "⌥X", null, SetHomework));
     }
 
+    private void BuildDayHighlightChoices()
+    {
+        DayHighlightChoices.Add(new(DayHighlightDisplay.Symbol(DayHighlightKind.Standout),
+            DayHighlightDisplay.Label(DayHighlightKind.Standout), "⇧1", DayHighlightKind.Standout, SetDayHighlight));
+        DayHighlightChoices.Add(new(DayHighlightDisplay.Symbol(DayHighlightKind.Sleepy),
+            DayHighlightDisplay.Label(DayHighlightKind.Sleepy), "⇧2", DayHighlightKind.Sleepy, SetDayHighlight));
+        DayHighlightChoices.Add(new(DayHighlightDisplay.Symbol(DayHighlightKind.Rough),
+            DayHighlightDisplay.Label(DayHighlightKind.Rough), "⇧3", DayHighlightKind.Rough, SetDayHighlight));
+        DayHighlightChoices.Add(new("·", "Keine Markierung", "⇧X", null, SetDayHighlight));
+    }
+
     public void SelectAspect(int index)
     {
         if (index < 0 || index >= AspectRows.Count) return;
@@ -827,6 +845,17 @@ public partial class SeatAssessmentViewModel : ObservableObject
         if (clear || digit is 0 or 1 or 3 or 4 or 5 or 7 or 8) SetHomework(status);
     }
 
+    public void ApplyDayHighlightShortcut(int? digit, bool clear)
+    {
+        if (!CanEdit) return;
+        var kind = clear ? null : digit switch
+        {
+            1 => DayHighlightKind.Standout, 2 => DayHighlightKind.Sleepy, 3 => DayHighlightKind.Rough,
+            _ => (DayHighlightKind?)null,
+        };
+        if (clear || digit is 1 or 2 or 3) SetDayHighlight(kind);
+    }
+
     private void ApplyRating(string key, int? value)
     {
         if (!CanEdit || _entry is null) return;
@@ -857,13 +886,23 @@ public partial class SeatAssessmentViewModel : ObservableObject
         RefreshStatusChoices();
     }
 
+    private void SetDayHighlight(DayHighlightKind? kind)
+    {
+        if (!CanEdit || _entry is null) return;
+        _entry.DayHighlight = kind;
+        _entries.Save(_entry);
+        RefreshStatusChoices();
+    }
+
     private void RefreshStatusChoices()
     {
         AttendanceLabel = AttendanceDisplay.Label(_entry?.Attendance);
         HomeworkLabel = HomeworkDisplay.Label(_entry is null ? null : HomeworkDisplay.Effective(_entry));
+        DayHighlightLabel = DayHighlightDisplay.Label(_entry?.DayHighlight);
         foreach (var choice in AttendanceChoices) choice.IsSelected = choice.Status == _entry?.Attendance;
         var homework = _entry is null ? null : HomeworkDisplay.Effective(_entry);
         foreach (var choice in HomeworkChoices) choice.IsSelected = choice.Status == homework;
+        foreach (var choice in DayHighlightChoices) choice.IsSelected = choice.Kind == _entry?.DayHighlight;
     }
 }
 
@@ -966,6 +1005,17 @@ public partial class SeatHomeworkChoice(string symbol, string label, string shor
     [RelayCommand] private void Apply() => apply(Status);
 }
 
+public partial class SeatDayHighlightChoice(string symbol, string label, string shortcut,
+    DayHighlightKind? kind, Action<DayHighlightKind?> apply) : ObservableObject
+{
+    public string Symbol { get; } = symbol;
+    public string Label { get; } = label;
+    public string Shortcut { get; } = shortcut;
+    public DayHighlightKind? Kind { get; } = kind;
+    [ObservableProperty] private bool _isSelected;
+    [RelayCommand] private void Apply() => apply(Kind);
+}
+
 public partial class SeatingPlanDialogViewModel : ObservableObject
 {
     private readonly ISeatingPlanRepository _plans;