Arbeitszeit: Auswertung nach Kategorie/Gruppe + Pflichtstunden-Abgleich (Kapitel 6.3)

Dritter Tab "Auswertung": Zeitraum wahlweise Monat oder Schuljahr, Balken je Kategorie
und Gruppe. Neuer WorkloadSettingsService (gleiches JSON-Muster wie PeriodScheduleService)
für die Pflichtstundenzahl pro Woche, bewusst direkt im Auswertungs-Tab editierbar statt
in den Einstellungen, da das Feld nur dort gebraucht wird. Export (6.3.3) bleibt offen,
da er an das noch fehlende Kapitel 11 (Export-Infrastruktur) hängt.

LehrerApp.Desktop.Tests/WorkloadViewModelTests.cs

@@ -1,4 +1,5 @@
 using LehrerApp.Core.Models;
+using LehrerApp.Core.Services;
 using LehrerApp.Desktop.ViewModels.Workload;
 using Xunit;
 
@@ -346,3 +347,102 @@ public sealed class AddTimeEntryDialogViewModelTests
         Assert.NotEmpty(vm.TimeError);
     }
 }
+
+public sealed class WorkloadEvaluationViewModelTests
+{
+    private static WorkloadSettingsService BuildSettingsService()
+    {
+        var tempPath = System.IO.Path.Combine(
+            System.IO.Path.GetTempPath(), $"lehrerapp-workloadsettings-tests-{Guid.NewGuid():N}");
+        Directory.CreateDirectory(tempPath);
+        return new WorkloadSettingsService(tempPath);
+    }
+
+    [Fact]
+    public void MonatModus_ZeigtNurEintraegeDesGewaehltenMonats()
+    {
+        var entries = new FakeTimeEntries();
+        entries.Add(new TimeEntry { Category = "Korrektur", Date = new DateOnly(2026, 3, 10), DurationMinutes = 30 });
+        entries.Add(new TimeEntry { Category = "Korrektur", Date = new DateOnly(2026, 4, 1), DurationMinutes = 45 });
+
+        var vm = new WorkloadEvaluationViewModel(entries, new FakeGroups([]), BuildSettingsService(), new SchoolYearService())
+        {
+            SelectedYear = 2026,
+        };
+        vm.SelectedMonth = vm.MonthOptions[2]; // März
+
+        Assert.Equal("30 min (0.5 h)", vm.TotalMinutesDisplay);
+    }
+
+    [Fact]
+    public void CategorySummaries_GruppiertProKategorie()
+    {
+        var entries = new FakeTimeEntries();
+        entries.Add(new TimeEntry { Category = "Korrektur", Date = new DateOnly(2026, 3, 5), DurationMinutes = 30 });
+        entries.Add(new TimeEntry { Category = "Verwaltung", Date = new DateOnly(2026, 3, 6), DurationMinutes = 20 });
+
+        var vm = new WorkloadEvaluationViewModel(entries, new FakeGroups([]), BuildSettingsService(), new SchoolYearService())
+        {
+            SelectedYear = 2026,
+        };
+        vm.SelectedMonth = vm.MonthOptions[2];
+
+        Assert.Equal(2, vm.CategorySummaries.Count);
+        Assert.Contains(vm.CategorySummaries, s => s.Category == "Korrektur" && s.MinutesDisplay == "30 min");
+    }
+
+    [Fact]
+    public void GroupSummaries_ZeigtNurEintraegeMitGruppe()
+    {
+        var group = new LearningGroup { Name = "8a" };
+        var entries = new FakeTimeEntries();
+        entries.Add(new TimeEntry { Category = "X", GroupId = group.Id, Date = new DateOnly(2026, 3, 5), DurationMinutes = 30 });
+        entries.Add(new TimeEntry { Category = "X", GroupId = null, Date = new DateOnly(2026, 3, 6), DurationMinutes = 20 });
+
+        var vm = new WorkloadEvaluationViewModel(entries, new FakeGroups([group]), BuildSettingsService(), new SchoolYearService())
+        {
+            SelectedYear = 2026,
+        };
+        vm.SelectedMonth = vm.MonthOptions[2];
+
+        var summary = Assert.Single(vm.GroupSummaries);
+        Assert.Equal("8a", summary.GroupName);
+        Assert.Equal("30 min", summary.MinutesDisplay);
+    }
+
+    [Fact]
+    public void SchuljahrModus_UmfasstAugustBisJuli()
+    {
+        var entries = new FakeTimeEntries();
+        entries.Add(new TimeEntry { Category = "X", Date = new DateOnly(2025, 9, 1), DurationMinutes = 30 }); // im Schuljahr 2025/26
+        entries.Add(new TimeEntry { Category = "X", Date = new DateOnly(2026, 7, 30), DurationMinutes = 15 }); // im Schuljahr 2025/26
+        entries.Add(new TimeEntry { Category = "X", Date = new DateOnly(2026, 8, 5), DurationMinutes = 99 }); // schon Schuljahr 2026/27
+
+        var vm = new WorkloadEvaluationViewModel(entries, new FakeGroups([]), BuildSettingsService(), new SchoolYearService())
+        {
+            SelectedYear = 2025,
+            PeriodMode = WorkloadEvaluationViewModel.SchoolYearMode,
+        };
+
+        Assert.Equal("45 min (0.8 h)", vm.TotalMinutesDisplay);
+    }
+
+    [Fact]
+    public void SaveRequiredWeeklyHours_AktualisiertSollIstVergleich()
+    {
+        var entries = new FakeTimeEntries();
+        entries.Add(new TimeEntry { Category = "X", Date = new DateOnly(2026, 3, 2), DurationMinutes = 60 });
+
+        var vm = new WorkloadEvaluationViewModel(entries, new FakeGroups([]), BuildSettingsService(), new SchoolYearService())
+        {
+            SelectedYear = 2026,
+            RequiredWeeklyHoursText = "10",
+        };
+        vm.SelectedMonth = vm.MonthOptions[2];
+
+        vm.SaveRequiredWeeklyHoursCommand.Execute(null);
+
+        Assert.Contains("Soll:", vm.RequiredVsActualDisplay);
+        Assert.Contains("Ist: 1 h", vm.RequiredVsActualDisplay);
+    }
+}