Arbeitszeit: Zeiterfassung (Kapitel 6.2)

Neuer Tab "Zeiterfassung" neben "Aufgaben" (WorkloadViewModel als Tab-Container,
gleiches Muster wie GroupDetailViewModel): Timer mit Zuordnung zu Aufgabe/Kategorie,
manuelle Nacherfassung (Von-Bis oder Dauer), Wochenübersicht nach Kategorie, sowie
"X / Y min erfasst" direkt in der Aufgabenliste als Ist-vs-Soll-Vergleich.

LehrerApp.Desktop.Tests/Fakes.cs

@@ -280,6 +280,18 @@ public class FakeWorkTasks : IWorkTaskRepository
     public void Delete(Guid id) => _all.RemoveAll(t => t.Id == id);
 }
 
+public class FakeTimeEntries : ITimeEntryRepository
+{
+    private readonly List<TimeEntry> _all = [];
+    public void Add(TimeEntry e) => _all.Add(e);
+    public List<TimeEntry> GetByDate(DateOnly date) => _all.Where(e => e.Date == date).ToList();
+    public List<TimeEntry> GetByDateRange(DateOnly from, DateOnly to) =>
+        _all.Where(e => e.Date >= from && e.Date <= to).ToList();
+    public List<TimeEntry> GetByTask(Guid taskId) => _all.Where(e => e.TaskId == taskId).ToList();
+    public void Save(TimeEntry entry) { _all.RemoveAll(e => e.Id == entry.Id); _all.Add(entry); }
+    public void Delete(Guid id) => _all.RemoveAll(e => e.Id == id);
+}
+
 public class FakeReportGrades : IReportGradeRepository
 {
     private readonly List<ReportGrade> _all = [];

LehrerApp.Desktop.Tests/WorkloadViewModelTests.cs

@@ -12,7 +12,7 @@ public sealed class WorkTaskListViewModelTests
         var tasks = new FakeWorkTasks();
         tasks.Add(new WorkTask { Title = "Offen", Status = WorkTaskStatus.Open });
         tasks.Add(new WorkTask { Title = "Erledigt", Status = WorkTaskStatus.Done });
-        var vm = new WorkTaskListViewModel(tasks, new FakeGroups([]));
+        var vm = new WorkTaskListViewModel(tasks, new FakeGroups([]), new FakeTimeEntries());
 
         Assert.Single(vm.Tasks);
         Assert.Equal("Offen", vm.Tasks[0].Title);
@@ -23,7 +23,7 @@ public sealed class WorkTaskListViewModelTests
     {
         var tasks = new FakeWorkTasks();
         tasks.Add(new WorkTask { Title = "Erledigt", Status = WorkTaskStatus.Done });
-        var vm = new WorkTaskListViewModel(tasks, new FakeGroups([]))
+        var vm = new WorkTaskListViewModel(tasks, new FakeGroups([]), new FakeTimeEntries())
         {
             StatusFilter = WorkTaskListViewModel.AllFilter,
         };
@@ -37,7 +37,7 @@ public sealed class WorkTaskListViewModelTests
         var tasks = new FakeWorkTasks();
         tasks.Add(new WorkTask { Title = "Korrektur", Category = TaskCategory.Correction });
         tasks.Add(new WorkTask { Title = "Vorbereitung", Category = TaskCategory.Preparation });
-        var vm = new WorkTaskListViewModel(tasks, new FakeGroups([]))
+        var vm = new WorkTaskListViewModel(tasks, new FakeGroups([]), new FakeTimeEntries())
         {
             CategoryFilter = TaskCategoryDisplay.Label(TaskCategory.Correction),
         };
@@ -53,7 +53,7 @@ public sealed class WorkTaskListViewModelTests
         var tasks = new FakeWorkTasks();
         tasks.Add(new WorkTask { Title = "Mit Gruppe", GroupId = group.Id });
         tasks.Add(new WorkTask { Title = "Ohne Gruppe", GroupId = null });
-        var vm = new WorkTaskListViewModel(tasks, new FakeGroups([group]))
+        var vm = new WorkTaskListViewModel(tasks, new FakeGroups([group]), new FakeTimeEntries())
         {
             GroupFilter = WorkTaskListViewModel.NoGroupFilter,
         };
@@ -67,7 +67,7 @@ public sealed class WorkTaskListViewModelTests
     {
         var tasks = new FakeWorkTasks();
         tasks.Add(new WorkTask { Title = "T", Status = WorkTaskStatus.Open });
-        var vm = new WorkTaskListViewModel(tasks, new FakeGroups([]))
+        var vm = new WorkTaskListViewModel(tasks, new FakeGroups([]), new FakeTimeEntries())
         {
             StatusFilter = WorkTaskListViewModel.AllFilter,
         };
@@ -82,7 +82,7 @@ public sealed class WorkTaskListViewModelTests
     {
         var tasks = new FakeWorkTasks();
         tasks.Add(new WorkTask { Title = "T", Status = WorkTaskStatus.Done });
-        var vm = new WorkTaskListViewModel(tasks, new FakeGroups([]))
+        var vm = new WorkTaskListViewModel(tasks, new FakeGroups([]), new FakeTimeEntries())
         {
             StatusFilter = WorkTaskListViewModel.AllFilter,
         };
@@ -97,7 +97,7 @@ public sealed class WorkTaskListViewModelTests
     {
         var tasks = new FakeWorkTasks();
         tasks.Add(new WorkTask { Title = "T" });
-        var vm = new WorkTaskListViewModel(tasks, new FakeGroups([]));
+        var vm = new WorkTaskListViewModel(tasks, new FakeGroups([]), new FakeTimeEntries());
 
         vm.DeleteTaskCommand.Execute(vm.Tasks[0]);
 
@@ -108,7 +108,7 @@ public sealed class WorkTaskListViewModelTests
     public async Task AddTask_RuftOnEditTaskAufUndSpeichertErgebnis()
     {
         var tasks = new FakeWorkTasks();
-        var vm = new WorkTaskListViewModel(tasks, new FakeGroups([]));
+        var vm = new WorkTaskListViewModel(tasks, new FakeGroups([]), new FakeTimeEntries());
         vm.OnEditTask = _ => Task.FromResult<WorkTask?>(new WorkTask { Title = "Neu" });
 
         await vm.AddTaskCommand.ExecuteAsync(null);
@@ -124,7 +124,7 @@ public sealed class WorkTaskListViewModelTests
         tasks.Add(new WorkTask { Title = "Ohne Frist", DueDate = null });
         tasks.Add(new WorkTask { Title = "Spät fällig", DueDate = DateOnly.FromDateTime(DateTime.Today.AddDays(10)) });
         tasks.Add(new WorkTask { Title = "Bald fällig", DueDate = DateOnly.FromDateTime(DateTime.Today.AddDays(1)) });
-        var vm = new WorkTaskListViewModel(tasks, new FakeGroups([]));
+        var vm = new WorkTaskListViewModel(tasks, new FakeGroups([]), new FakeTimeEntries());
 
         Assert.Equal(["Bald fällig", "Spät fällig", "Ohne Frist"], vm.Tasks.Select(t => t.Title));
     }
@@ -193,3 +193,156 @@ public sealed class AddEditWorkTaskDialogViewModelTests
         Assert.Equal(WorkTaskStatus.InProgress, vm.Result.Status);
     }
 }
+
+public sealed class TimeTrackingViewModelTests
+{
+    [Fact]
+    public void StartStopTimer_SpeichertZeiteintragMitMindestensEinerMinute()
+    {
+        var entries = new FakeTimeEntries();
+        var vm = new TimeTrackingViewModel(entries, new FakeWorkTasks())
+        {
+            SelectedTimerCategory = TaskCategoryDisplay.Label(TaskCategory.Correction),
+        };
+
+        vm.StartTimerCommand.Execute(null);
+        Assert.True(vm.IsTimerRunning);
+
+        vm.StopTimerCommand.Execute(null);
+
+        Assert.False(vm.IsTimerRunning);
+        var saved = Assert.Single(entries.GetByDate(DateOnly.FromDateTime(DateTime.Today)));
+        Assert.True(saved.DurationMinutes >= 1);
+        Assert.Equal(TaskCategoryDisplay.Label(TaskCategory.Correction), saved.Category);
+    }
+
+    [Fact]
+    public void SelectedTimerTask_UebernimmtDessenKategorie()
+    {
+        var task = new WorkTask { Title = "T", Category = TaskCategory.Meeting };
+        var tasks = new FakeWorkTasks();
+        tasks.Add(task);
+        var vm = new TimeTrackingViewModel(new FakeTimeEntries(), tasks);
+
+        vm.SelectedTimerTask = task;
+
+        Assert.Equal(TaskCategoryDisplay.Label(TaskCategory.Meeting), vm.SelectedTimerCategory);
+    }
+
+    [Fact]
+    public void Load_ZeigtNurEintraegeDerAktuellenWoche()
+    {
+        var entries = new FakeTimeEntries();
+        entries.Add(new TimeEntry { Category = "X", Date = DateOnly.FromDateTime(DateTime.Today), DurationMinutes = 30 });
+        entries.Add(new TimeEntry { Category = "X", Date = DateOnly.FromDateTime(DateTime.Today).AddDays(-30), DurationMinutes = 45 });
+
+        var vm = new TimeTrackingViewModel(entries, new FakeWorkTasks());
+
+        Assert.Single(vm.WeekEntries);
+        Assert.Equal(30, vm.WeekEntries[0].Model.DurationMinutes);
+    }
+
+    [Fact]
+    public void CategorySummaries_GruppiertUndSummiertProKategorie()
+    {
+        var today = DateOnly.FromDateTime(DateTime.Today);
+        var entries = new FakeTimeEntries();
+        entries.Add(new TimeEntry { Category = "Korrektur", Date = today, DurationMinutes = 30 });
+        entries.Add(new TimeEntry { Category = "Korrektur", Date = today, DurationMinutes = 20 });
+        entries.Add(new TimeEntry { Category = "Verwaltung", Date = today, DurationMinutes = 10 });
+
+        var vm = new TimeTrackingViewModel(entries, new FakeWorkTasks());
+
+        var korrektur = vm.CategorySummaries.Single(s => s.Category == "Korrektur");
+        Assert.Equal("50 min", korrektur.MinutesDisplay);
+        Assert.Equal(1.0, korrektur.BarFraction);
+        Assert.Equal("60 min diese Woche", vm.TotalWeekMinutesDisplay);
+    }
+
+    [Fact]
+    public void DeleteEntry_EntferntEintragAusDerWoche()
+    {
+        var entries = new FakeTimeEntries();
+        entries.Add(new TimeEntry { Category = "X", Date = DateOnly.FromDateTime(DateTime.Today), DurationMinutes = 30 });
+        var vm = new TimeTrackingViewModel(entries, new FakeWorkTasks());
+
+        vm.DeleteEntryCommand.Execute(vm.WeekEntries[0]);
+
+        Assert.Empty(vm.WeekEntries);
+    }
+
+    [Fact]
+    public async Task AddEntry_RuftOnAddEntryAufUndSpeichertErgebnis()
+    {
+        var entries = new FakeTimeEntries();
+        var vm = new TimeTrackingViewModel(entries, new FakeWorkTasks());
+        vm.OnAddEntry = () => Task.FromResult<TimeEntry?>(
+            new TimeEntry { Category = "X", Date = DateOnly.FromDateTime(DateTime.Today), DurationMinutes = 15 });
+
+        await vm.AddEntryCommand.ExecuteAsync(null);
+
+        Assert.Single(vm.WeekEntries);
+    }
+}
+
+public sealed class AddTimeEntryDialogViewModelTests
+{
+    [Fact]
+    public void Save_MitDauer_ErzeugtEintrag()
+    {
+        var vm = new AddTimeEntryDialogViewModel([])
+        {
+            DateText = "10.01.2026",
+            DurationText = "45",
+        };
+
+        vm.SaveCommand.Execute(null);
+
+        Assert.NotNull(vm.Result);
+        Assert.Equal(45, vm.Result!.DurationMinutes);
+        Assert.Equal(new DateOnly(2026, 1, 10), vm.Result.Date);
+    }
+
+    [Fact]
+    public void Save_MitVonBis_BerechnetDauer()
+    {
+        var vm = new AddTimeEntryDialogViewModel([])
+        {
+            DateText = "10.01.2026",
+            StartTimeText = "14:00",
+            EndTimeText = "14:30",
+        };
+
+        vm.SaveCommand.Execute(null);
+
+        Assert.NotNull(vm.Result);
+        Assert.Equal(30, vm.Result!.DurationMinutes);
+    }
+
+    [Fact]
+    public void Save_OhneDauerUndOhneZeiten_SetztFehler()
+    {
+        var vm = new AddTimeEntryDialogViewModel([]) { DateText = "10.01.2026" };
+
+        vm.SaveCommand.Execute(null);
+
+        Assert.Null(vm.Result);
+        Assert.NotEmpty(vm.TimeError);
+    }
+
+    [Fact]
+    public void Save_EndeVorBeginn_SetztFehler()
+    {
+        var vm = new AddTimeEntryDialogViewModel([])
+        {
+            DateText = "10.01.2026",
+            StartTimeText = "14:30",
+            EndTimeText = "14:00",
+        };
+
+        vm.SaveCommand.Execute(null);
+
+        Assert.Null(vm.Result);
+        Assert.NotEmpty(vm.TimeError);
+    }
+}

LehrerApp.Desktop/AppBootstrapper.cs

@@ -189,6 +189,8 @@ public static class AppBootstrapper
         services.AddSingleton<StudentListViewModel>();
         services.AddSingleton<TimetableViewModel>();
         services.AddSingleton<WorkTaskListViewModel>();
+        services.AddSingleton<TimeTrackingViewModel>();
+        services.AddSingleton<WorkloadViewModel>();
 
         // Transient: neue Instanz pro Navigation (für Detailseiten)
         services.AddTransient<GroupDetailViewModel>();

LehrerApp.Desktop/ViewModels/MainWindowViewModel.cs

@@ -89,10 +89,12 @@ public partial class MainWindowViewModel : ObservableObject
         return timetable;
     }
 
-    private WorkTaskListViewModel GetWorkload()
+    private WorkloadViewModel GetWorkload()
     {
-        var workload = _services.GetRequiredService<WorkTaskListViewModel>();
+        var workload = _services.GetRequiredService<WorkloadViewModel>();
-        workload.Load();
+        workload.Tasks.Load();
+        workload.TimeTracking.Load();
+        workload.ActiveTabIndex = 0;
         return workload;
     }
 

LehrerApp.Desktop/ViewModels/Workload/WorkloadViewModels.cs

@@ -60,6 +60,7 @@ public partial class WorkTaskListViewModel : ObservableObject
 {
     private readonly IWorkTaskRepository _tasks;
     private readonly IGroupRepository _groups;
+    private readonly ITimeEntryRepository _timeEntries;
 
     public const string AllFilter = "Alle";
     public const string ActiveFilter = "Offene Aufgaben";
@@ -81,10 +82,12 @@ public partial class WorkTaskListViewModel : ObservableObject
 
     private Dictionary<Guid, string> _groupNames = [];
 
-    public WorkTaskListViewModel(IWorkTaskRepository tasks, IGroupRepository groups)
+    public WorkTaskListViewModel(IWorkTaskRepository tasks, IGroupRepository groups,
+        ITimeEntryRepository timeEntries)
     {
         _tasks = tasks;
         _groups = groups;
+        _timeEntries = timeEntries;
         Load();
     }
 
@@ -131,7 +134,11 @@ public partial class WorkTaskListViewModel : ObservableObject
 
         // Fälligkeit: fällige zuerst, unbefristete ans Ende (6.1.1).
         foreach (var t in all.OrderBy(t => t.DueDate ?? DateOnly.MaxValue).ThenBy(t => t.Title))
-            Tasks.Add(new WorkTaskListItem(t, _groupNames.GetValueOrDefault(t.GroupId ?? Guid.Empty)));
+        {
+            // Ist-Zeit (6.2.4): Summe aller mit der Aufgabe verknüpften Zeiteinträge.
+            var actualMinutes = _timeEntries.GetByTask(t.Id).Sum(e => e.DurationMinutes);
+            Tasks.Add(new WorkTaskListItem(t, _groupNames.GetValueOrDefault(t.GroupId ?? Guid.Empty), actualMinutes));
+        }
 
         OnPropertyChanged(nameof(CountSummary));
     }
@@ -174,7 +181,7 @@ public partial class WorkTaskListViewModel : ObservableObject
     }
 }
 
-public class WorkTaskListItem(WorkTask model, string? groupName)
+public class WorkTaskListItem(WorkTask model, string? groupName, int actualMinutes = 0)
 {
     public WorkTask Model { get; } = model;
     public string Title => Model.Title;
@@ -187,6 +194,12 @@ public class WorkTaskListItem(WorkTask model, string? groupName)
     public string StatusLabel => WorkTaskStatusDisplay.Label(Model.Status);
     public string StatusColorHex => WorkTaskStatusDisplay.ColorHex(Model.Status);
     public string EstimatedMinutesDisplay => Model.EstimatedMinutes is { } m ? $"{m} min" : "";
+
+    // Ist-Zeit vs. Schätzung (6.2.4) — nur anzeigen, wenn tatsächlich etwas erfasst wurde.
+    public bool HasActualTime => actualMinutes > 0;
+    public string ActualVsEstimateDisplay => Model.EstimatedMinutes is { } estimate
+        ? $"{actualMinutes} / {estimate} min erfasst"
+        : $"{actualMinutes} min erfasst";
 }
 
 // ── Dialog: Aufgabe anlegen/bearbeiten (6.1.2) ───────────────────────────────
@@ -264,3 +277,224 @@ public partial class AddEditWorkTaskDialogViewModel : ObservableObject
         };
     }
 }
+
+// ── Zeiterfassung (6.2) ──────────────────────────────────────────────────────
+
+public partial class TimeTrackingViewModel : ObservableObject
+{
+    private readonly ITimeEntryRepository _entries;
+    private readonly IWorkTaskRepository _tasks;
+
+    public const string NoTaskOption = "Keine Aufgabe";
+
+    [ObservableProperty] private bool _isTimerRunning;
+    [ObservableProperty] private DateTime? _timerStartedAt;
+    [ObservableProperty] private WorkTask? _selectedTimerTask;
+    [ObservableProperty] private string _selectedTimerCategory = TaskCategoryDisplay.Options[0];
+
+    public List<string> CategoryOptions { get; } = [.. TaskCategoryDisplay.Options];
+    public List<WorkTask> OpenTasks { get; private set; } = [];
+    public string RunningSinceDisplay => TimerStartedAt is { } started
+        ? $"Läuft seit {started:HH:mm} Uhr"
+        : "";
+
+    public ObservableCollection<TimeEntryListItem> WeekEntries { get; } = [];
+    public ObservableCollection<CategoryWeekSummary> CategorySummaries { get; } = [];
+    public string TotalWeekMinutesDisplay => $"{WeekEntries.Sum(e => e.Model.DurationMinutes)} min diese Woche";
+
+    public Func<Task<TimeEntry?>>? OnAddEntry { get; set; }
+
+    public TimeTrackingViewModel(ITimeEntryRepository entries, IWorkTaskRepository tasks)
+    {
+        _entries = entries;
+        _tasks = tasks;
+        Load();
+    }
+
+    partial void OnSelectedTimerTaskChanged(WorkTask? value)
+    {
+        if (value is not null) SelectedTimerCategory = TaskCategoryDisplay.Label(value.Category);
+    }
+
+    public void Load()
+    {
+        OpenTasks = _tasks.GetAll().Where(t => t.Status != WorkTaskStatus.Done).ToList();
+        OnPropertyChanged(nameof(OpenTasks));
+        Refresh();
+    }
+
+    private void Refresh()
+    {
+        var today = DateOnly.FromDateTime(DateTime.Today);
+        var monday = today.AddDays(-((int)today.DayOfWeek + 6) % 7);
+        var sunday = monday.AddDays(6);
+
+        var weekEntries = _entries.GetByDateRange(monday, sunday);
+        var taskTitles = _tasks.GetAll().ToDictionary(t => t.Id, t => t.Title);
+
+        WeekEntries.Clear();
+        foreach (var e in weekEntries.OrderByDescending(e => e.Date).ThenByDescending(e => e.StartTime))
+            WeekEntries.Add(new TimeEntryListItem(e, e.TaskId is { } id ? taskTitles.GetValueOrDefault(id) : null));
+
+        CategorySummaries.Clear();
+        var maxMinutes = weekEntries.Count > 0
+            ? weekEntries.GroupBy(e => e.Category).Max(g => g.Sum(e => e.DurationMinutes))
+            : 0;
+        foreach (var group in weekEntries.GroupBy(e => e.Category).OrderByDescending(g => g.Sum(e => e.DurationMinutes)))
+        {
+            var minutes = group.Sum(e => e.DurationMinutes);
+            CategorySummaries.Add(new CategoryWeekSummary(
+                string.IsNullOrWhiteSpace(group.Key) ? "Ohne Kategorie" : group.Key,
+                minutes, maxMinutes > 0 ? minutes / (double)maxMinutes : 0));
+        }
+
+        OnPropertyChanged(nameof(TotalWeekMinutesDisplay));
+    }
+
+    [RelayCommand]
+    private void StartTimer()
+    {
+        IsTimerRunning = true;
+        TimerStartedAt = DateTime.Now;
+        OnPropertyChanged(nameof(RunningSinceDisplay));
+    }
+
+    [RelayCommand]
+    private void StopTimer()
+    {
+        if (TimerStartedAt is not { } startedAt) return;
+        var endedAt = DateTime.Now;
+        var minutes = Math.Max(1, (int)Math.Round((endedAt - startedAt).TotalMinutes));
+
+        _entries.Save(new TimeEntry
+        {
+            TaskId          = SelectedTimerTask?.Id,
+            Category        = SelectedTimerCategory,
+            GroupId         = SelectedTimerTask?.GroupId,
+            Date            = DateOnly.FromDateTime(startedAt),
+            StartTime       = TimeOnly.FromDateTime(startedAt),
+            EndTime         = TimeOnly.FromDateTime(endedAt),
+            DurationMinutes = minutes,
+        });
+
+        IsTimerRunning = false;
+        TimerStartedAt = null;
+        OnPropertyChanged(nameof(RunningSinceDisplay));
+        Refresh();
+    }
+
+    [RelayCommand]
+    private async Task AddEntry()
+    {
+        if (OnAddEntry is null) return;
+        var result = await OnAddEntry();
+        if (result is null) return;
+        _entries.Save(result);
+        Refresh();
+    }
+
+    [RelayCommand]
+    private void DeleteEntry(TimeEntryListItem? item)
+    {
+        if (item is null) return;
+        _entries.Delete(item.Model.Id);
+        Refresh();
+    }
+}
+
+public class TimeEntryListItem(TimeEntry model, string? taskTitle)
+{
+    public TimeEntry Model { get; } = model;
+    public string DateDisplay => Model.Date.ToString("dd.MM.yyyy", CultureInfo.InvariantCulture);
+    public string Category => string.IsNullOrWhiteSpace(Model.Category) ? "Ohne Kategorie" : Model.Category;
+    public string TaskTitle => taskTitle ?? "";
+    public string CategoryAndTaskDisplay => string.IsNullOrEmpty(TaskTitle) ? Category : $"{Category} · {TaskTitle}";
+    public string DurationDisplay => $"{Model.DurationMinutes} min";
+    public string Description => Model.Description ?? "";
+}
+
+public class CategoryWeekSummary(string category, int minutes, double barFraction)
+{
+    public string Category { get; } = category;
+    public string MinutesDisplay { get; } = $"{minutes} min";
+    public double BarFraction { get; } = barFraction;
+}
+
+// ── Dialog: Zeiteintrag nacherfassen (6.2.2) ─────────────────────────────────
+
+public partial class AddTimeEntryDialogViewModel : ObservableObject
+{
+    [ObservableProperty] private string _dateText = DateTime.Today.ToString("dd.MM.yyyy", CultureInfo.InvariantCulture);
+    [ObservableProperty] private string _selectedCategory = TaskCategoryDisplay.Options[0];
+    [ObservableProperty] private WorkTask? _selectedTask;
+    [ObservableProperty] private string _startTimeText = "";
+    [ObservableProperty] private string _endTimeText = "";
+    [ObservableProperty] private string _durationText = "";
+    [ObservableProperty] private string _description = "";
+    [ObservableProperty] private string _dateError = "";
+    [ObservableProperty] private string _timeError = "";
+
+    public List<string> CategoryOptions { get; } = [.. TaskCategoryDisplay.Options];
+    public List<WorkTask> Tasks { get; }
+    public TimeEntry? Result { get; private set; }
+
+    public AddTimeEntryDialogViewModel(List<WorkTask> tasks) => Tasks = tasks;
+
+    partial void OnSelectedTaskChanged(WorkTask? value)
+    {
+        if (value is not null) SelectedCategory = TaskCategoryDisplay.Label(value.Category);
+    }
+
+    [RelayCommand]
+    private void Save()
+    {
+        DateError = ""; TimeError = "";
+        var valid = true;
+
+        if (!DateOnly.TryParseExact(DateText, "dd.MM.yyyy", null, DateTimeStyles.None, out var date))
+        { DateError = "Format TT.MM.JJJJ."; valid = false; }
+
+        TimeOnly? start = null, end = null;
+        int? duration = null;
+
+        if (!string.IsNullOrWhiteSpace(DurationText))
+        {
+            if (!int.TryParse(DurationText, out var m) || m <= 0)
+            { TimeError = "Dauer: ganze Zahl > 0 erwartet."; valid = false; }
+            else duration = m;
+        }
+        else if (!string.IsNullOrWhiteSpace(StartTimeText) || !string.IsNullOrWhiteSpace(EndTimeText))
+        {
+            if (!TimeOnly.TryParseExact(StartTimeText, "HH:mm", null, DateTimeStyles.None, out var s)
+                || !TimeOnly.TryParseExact(EndTimeText, "HH:mm", null, DateTimeStyles.None, out var e)
+                || e <= s)
+            { TimeError = "Format HH:mm, Ende muss nach Beginn liegen."; valid = false; }
+            else { start = s; end = e; duration = (int)(e - s).TotalMinutes; }
+        }
+        else { TimeError = "Dauer oder Von/Bis erforderlich."; valid = false; }
+
+        if (!valid) return;
+
+        Result = new TimeEntry
+        {
+            TaskId          = SelectedTask?.Id,
+            Category        = SelectedCategory,
+            GroupId         = SelectedTask?.GroupId,
+            Date            = date,
+            StartTime       = start,
+            EndTime         = end,
+            DurationMinutes = duration!.Value,
+            Description     = string.IsNullOrWhiteSpace(Description) ? null : Description.Trim(),
+        };
+    }
+}
+
+// ── Container: Arbeitszeit-Seite mit Tabs "Aufgaben"/"Zeiterfassung" ─────────
+
+public partial class WorkloadViewModel(WorkTaskListViewModel tasks, TimeTrackingViewModel timeTracking) : ObservableObject
+{
+    [ObservableProperty] private int _activeTabIndex;
+
+    public WorkTaskListViewModel Tasks { get; } = tasks;
+    public TimeTrackingViewModel TimeTracking { get; } = timeTracking;
+}

LehrerApp.Desktop/Views/MainWindow.axaml

@@ -55,8 +55,8 @@
       <DataTemplate DataType="vmp:TimetableViewModel">
         <vp:TimetableView/>
       </DataTemplate>
-      <DataTemplate DataType="vmw:WorkTaskListViewModel">
+      <DataTemplate DataType="vmw:WorkloadViewModel">
-        <vw:WorkTaskListView/>
+        <vw:WorkloadView/>
       </DataTemplate>
       <DataTemplate DataType="vm:PlaceholderViewModel">
         <views:PlaceholderView/>

LehrerApp.Desktop/Views/Workload/AddTimeEntryDialog.axaml

@@ -0,0 +1,72 @@
+<Window xmlns="https://github.com/avaloniaui"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        xmlns:vm="clr-namespace:LehrerApp.Desktop.ViewModels.Workload"
+        xmlns:models="clr-namespace:LehrerApp.Core.Models;assembly=LehrerApp.Core"
+        x:Class="LehrerApp.Desktop.Views.Workload.AddTimeEntryDialog"
+        x:DataType="vm:AddTimeEntryDialogViewModel"
+        Title="Zeit nacherfassen"
+        Width="420" Height="440" MinWidth="380" MinHeight="400"
+        CanResize="True" WindowStartupLocation="CenterOwner">
+
+  <Grid RowDefinitions="*,Auto" Margin="24">
+    <ScrollViewer Grid.Row="0">
+      <StackPanel Spacing="14" Margin="0,0,12,0">
+        <TextBlock Text="Zeit nacherfassen" Classes="dialogtitle"/>
+
+        <Grid ColumnDefinitions="*,8,*">
+          <StackPanel Grid.Column="0" Spacing="4">
+            <TextBlock Text="Datum *" FontSize="12" Opacity="0.7"/>
+            <TextBox Text="{Binding DateText}" PlaceholderText="TT.MM.JJJJ"/>
+            <TextBlock Text="{Binding DateError}" Foreground="Red" FontSize="11"
+                       IsVisible="{Binding DateError, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"/>
+          </StackPanel>
+          <StackPanel Grid.Column="2" Spacing="4">
+            <TextBlock Text="Kategorie" FontSize="12" Opacity="0.7"/>
+            <ComboBox ItemsSource="{Binding CategoryOptions}" SelectedItem="{Binding SelectedCategory}"
+                      HorizontalAlignment="Stretch"/>
+          </StackPanel>
+        </Grid>
+
+        <StackPanel Spacing="4">
+          <TextBlock Text="Aufgabe (optional)" FontSize="12" Opacity="0.7"/>
+          <ComboBox ItemsSource="{Binding Tasks}" SelectedItem="{Binding SelectedTask}"
+                    HorizontalAlignment="Stretch" PlaceholderText="Keine Aufgabe">
+            <ComboBox.ItemTemplate>
+              <DataTemplate x:DataType="models:WorkTask">
+                <TextBlock Text="{Binding Title}"/>
+              </DataTemplate>
+            </ComboBox.ItemTemplate>
+          </ComboBox>
+        </StackPanel>
+
+        <Grid ColumnDefinitions="*,8,*">
+          <StackPanel Grid.Column="0" Spacing="4">
+            <TextBlock Text="Von" FontSize="12" Opacity="0.7"/>
+            <TextBox Text="{Binding StartTimeText}" PlaceholderText="HH:mm"/>
+          </StackPanel>
+          <StackPanel Grid.Column="2" Spacing="4">
+            <TextBlock Text="Bis" FontSize="12" Opacity="0.7"/>
+            <TextBox Text="{Binding EndTimeText}" PlaceholderText="HH:mm"/>
+          </StackPanel>
+        </Grid>
+
+        <StackPanel Spacing="4">
+          <TextBlock Text="Oder Dauer in min" FontSize="12" Opacity="0.7"/>
+          <TextBox Text="{Binding DurationText}" PlaceholderText="z.B. 30"/>
+          <TextBlock Text="{Binding TimeError}" Foreground="Red" FontSize="11"
+                     IsVisible="{Binding TimeError, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"/>
+        </StackPanel>
+
+        <StackPanel Spacing="4">
+          <TextBlock Text="Notiz (optional)" FontSize="12" Opacity="0.7"/>
+          <TextBox Text="{Binding Description}"/>
+        </StackPanel>
+      </StackPanel>
+    </ScrollViewer>
+
+    <Grid Grid.Row="1" ColumnDefinitions="*,8,*" Margin="0,20,0,0">
+      <Button Grid.Column="0" Content="Abbrechen" HorizontalAlignment="Stretch" Click="OnCancel"/>
+      <Button Grid.Column="2" Content="Speichern" HorizontalAlignment="Stretch" Click="OnSave"/>
+    </Grid>
+  </Grid>
+</Window>

LehrerApp.Desktop/Views/Workload/AddTimeEntryDialog.axaml.cs

@@ -0,0 +1,21 @@
+using Avalonia.Controls;
+using Avalonia.Interactivity;
+using LehrerApp.Desktop.ViewModels.Workload;
+
+namespace LehrerApp.Desktop.Views.Workload;
+
+public partial class AddTimeEntryDialog : Window
+{
+    public AddTimeEntryDialog() => InitializeComponent();
+
+    private void OnSave(object? s, RoutedEventArgs e)
+    {
+        if (DataContext is AddTimeEntryDialogViewModel vm && vm.SaveCommand.CanExecute(null))
+        {
+            vm.SaveCommand.Execute(null);
+            if (vm.Result is not null) Close(true);
+        }
+    }
+
+    private void OnCancel(object? s, RoutedEventArgs e) => Close(false);
+}

LehrerApp.Desktop/Views/Workload/TimeTrackingView.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.Workload"
+             xmlns:models="clr-namespace:LehrerApp.Core.Models;assembly=LehrerApp.Core"
+             x:Class="LehrerApp.Desktop.Views.Workload.TimeTrackingView"
+             x:DataType="vm:TimeTrackingViewModel">
+  <ScrollViewer>
+    <StackPanel Margin="20,16" Spacing="16">
+
+      <!-- Timer (6.2.1) -->
+      <Border Background="{DynamicResource SystemControlBackgroundAltHighBrush}" CornerRadius="8" Padding="16">
+        <StackPanel Spacing="10">
+          <TextBlock Text="Timer" FontWeight="SemiBold" FontSize="14"/>
+          <Grid ColumnDefinitions="*,8,*" IsEnabled="{Binding !IsTimerRunning}">
+            <StackPanel Grid.Column="0" Spacing="4">
+              <TextBlock Text="Aufgabe (optional)" FontSize="12" Opacity="0.7"/>
+              <ComboBox ItemsSource="{Binding OpenTasks}" SelectedItem="{Binding SelectedTimerTask}"
+                        HorizontalAlignment="Stretch" PlaceholderText="Keine Aufgabe">
+                <ComboBox.ItemTemplate>
+                  <DataTemplate x:DataType="models:WorkTask">
+                    <TextBlock Text="{Binding Title}"/>
+                  </DataTemplate>
+                </ComboBox.ItemTemplate>
+              </ComboBox>
+            </StackPanel>
+            <StackPanel Grid.Column="2" Spacing="4">
+              <TextBlock Text="Kategorie" FontSize="12" Opacity="0.7"/>
+              <ComboBox ItemsSource="{Binding CategoryOptions}" SelectedItem="{Binding SelectedTimerCategory}"
+                        HorizontalAlignment="Stretch"/>
+            </StackPanel>
+          </Grid>
+          <Grid ColumnDefinitions="Auto,*">
+            <Button Grid.Column="0" Content="▶ Start" Command="{Binding StartTimerCommand}"
+                    IsVisible="{Binding !IsTimerRunning}"/>
+            <Button Grid.Column="0" Content="■ Stop" Command="{Binding StopTimerCommand}"
+                    IsVisible="{Binding IsTimerRunning}"/>
+            <TextBlock Grid.Column="1" Text="{Binding RunningSinceDisplay}" VerticalAlignment="Center"
+                       Margin="12,0,0,0" FontWeight="SemiBold"/>
+          </Grid>
+        </StackPanel>
+      </Border>
+
+      <!-- Wochenübersicht (6.2.3) -->
+      <Border Background="{DynamicResource SystemControlBackgroundAltHighBrush}" CornerRadius="8" Padding="16">
+        <StackPanel Spacing="10">
+          <Grid ColumnDefinitions="*,Auto">
+            <TextBlock Grid.Column="0" Text="Diese Woche" FontWeight="SemiBold" FontSize="14"/>
+            <TextBlock Grid.Column="1" Text="{Binding TotalWeekMinutesDisplay}" Opacity="0.7" FontSize="12"/>
+          </Grid>
+          <ItemsControl ItemsSource="{Binding CategorySummaries}">
+            <ItemsControl.ItemTemplate>
+              <DataTemplate x:DataType="vm:CategoryWeekSummary">
+                <Grid ColumnDefinitions="120,*,60" Margin="0,3">
+                  <TextBlock Grid.Column="0" Text="{Binding Category}" FontSize="12" VerticalAlignment="Center"/>
+                  <ProgressBar Grid.Column="1" Value="{Binding BarFraction}" Maximum="1" Height="8"
+                               VerticalAlignment="Center" Margin="8,0"/>
+                  <TextBlock Grid.Column="2" Text="{Binding MinutesDisplay}" FontSize="12"
+                             HorizontalAlignment="Right" VerticalAlignment="Center"/>
+                </Grid>
+              </DataTemplate>
+            </ItemsControl.ItemTemplate>
+          </ItemsControl>
+          <TextBlock Text="Noch keine Zeiten diese Woche erfasst." Opacity="0.6" FontSize="12"
+                     IsVisible="{Binding !CategorySummaries.Count}"/>
+        </StackPanel>
+      </Border>
+
+      <!-- Einträge / Nacherfassung (6.2.2) -->
+      <Grid ColumnDefinitions="*,Auto">
+        <TextBlock Grid.Column="0" Text="Einträge" FontWeight="SemiBold" FontSize="14" VerticalAlignment="Center"/>
+        <Button Grid.Column="1" Content="＋ Nacherfassen" Command="{Binding AddEntryCommand}"/>
+      </Grid>
+
+      <ItemsControl ItemsSource="{Binding WeekEntries}">
+        <ItemsControl.ItemTemplate>
+          <DataTemplate x:DataType="vm:TimeEntryListItem">
+            <Border Background="{DynamicResource SystemControlBackgroundAltHighBrush}"
+                    CornerRadius="6" Padding="12,8" Margin="0,0,0,6">
+              <Grid ColumnDefinitions="80,*,Auto,Auto">
+                <TextBlock Grid.Column="0" Text="{Binding DateDisplay}" FontSize="12" Opacity="0.6"
+                           VerticalAlignment="Center"/>
+                <StackPanel Grid.Column="1" Margin="8,0" VerticalAlignment="Center">
+                  <TextBlock Text="{Binding CategoryAndTaskDisplay}" FontSize="13"/>
+                  <TextBlock Text="{Binding Description}" FontSize="11" Opacity="0.6"
+                             IsVisible="{Binding Description, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"/>
+                </StackPanel>
+                <TextBlock Grid.Column="2" Text="{Binding DurationDisplay}" VerticalAlignment="Center"
+                           Margin="0,0,10,0" FontSize="12"/>
+                <Button Grid.Column="3" Content="Löschen" FontSize="11" Padding="8,3"
+                        Command="{Binding $parent[ItemsControl].((vm:TimeTrackingViewModel)DataContext).DeleteEntryCommand}"
+                        CommandParameter="{Binding}"/>
+              </Grid>
+            </Border>
+          </DataTemplate>
+        </ItemsControl.ItemTemplate>
+      </ItemsControl>
+      <TextBlock Text="Noch keine Einträge diese Woche." Opacity="0.6" Margin="4,4"
+                 IsVisible="{Binding !WeekEntries.Count}"/>
+    </StackPanel>
+  </ScrollViewer>
+</UserControl>

LehrerApp.Desktop/Views/Workload/TimeTrackingView.axaml.cs

@@ -0,0 +1,32 @@
+using Avalonia.Controls;
+using LehrerApp.Core.Interfaces;
+using LehrerApp.Core.Models;
+using LehrerApp.Desktop.ViewModels.Workload;
+using Microsoft.Extensions.DependencyInjection;
+
+namespace LehrerApp.Desktop.Views.Workload;
+
+public partial class TimeTrackingView : UserControl
+{
+    public TimeTrackingView() => InitializeComponent();
+
+    protected override void OnDataContextChanged(EventArgs e)
+    {
+        base.OnDataContextChanged(e);
+        if (DataContext is TimeTrackingViewModel vm)
+            vm.OnAddEntry = ShowAddEntryDialog;
+    }
+
+    private async Task<TimeEntry?> ShowAddEntryDialog()
+    {
+        var owner = TopLevel.GetTopLevel(this) as Window;
+        if (owner is null) return null;
+
+        var tasks = App.Services.GetRequiredService<IWorkTaskRepository>()
+            .GetAll().Where(t => t.Status != WorkTaskStatus.Done).ToList();
+        var vm = new AddTimeEntryDialogViewModel(tasks);
+        var dialog = new AddTimeEntryDialog { DataContext = vm };
+        await dialog.ShowDialog<bool>(owner);
+        return vm.Result;
+    }
+}

LehrerApp.Desktop/Views/Workload/WorkTaskListView.axaml

@@ -1,30 +1,20 @@
 <UserControl xmlns="https://github.com/avaloniaui"
              xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
              xmlns:vm="clr-namespace:LehrerApp.Desktop.ViewModels.Workload"
-             xmlns:shared="clr-namespace:LehrerApp.Desktop.Views.Shared"
              x:Class="LehrerApp.Desktop.Views.Workload.WorkTaskListView"
              x:DataType="vm:WorkTaskListViewModel">
-  <Grid RowDefinitions="Auto,Auto,*">
+  <Grid RowDefinitions="Auto,*">
-    <Border Grid.Row="0" Padding="20,16"
+    <Grid Grid.Row="0" ColumnDefinitions="Auto,Auto,Auto,*,Auto" Margin="16,14,16,4" VerticalAlignment="Center">
-            BorderBrush="{DynamicResource SystemControlForegroundBaseLowBrush}"
-            BorderThickness="0,0,0,1">
-      <Grid ColumnDefinitions="*,Auto">
-        <shared:PageHeader Grid.Column="0" Title="Arbeitszeit" Subtitle="{Binding CountSummary}"/>
-        <Button Grid.Column="1" Content="＋ Neue Aufgabe"
-                Command="{Binding AddTaskCommand}" VerticalAlignment="Center"/>
-      </Grid>
-    </Border>
-
-    <Grid Grid.Row="1" ColumnDefinitions="Auto,Auto,Auto" Margin="16,10" HorizontalAlignment="Left">
       <ComboBox Grid.Column="0" ItemsSource="{Binding StatusFilterOptions}"
                 SelectedItem="{Binding StatusFilter}" Margin="0,0,8,0"/>
       <ComboBox Grid.Column="1" ItemsSource="{Binding CategoryFilterOptions}"
                 SelectedItem="{Binding CategoryFilter}" Margin="0,0,8,0"/>
       <ComboBox Grid.Column="2" ItemsSource="{Binding GroupFilterOptions}"
                 SelectedItem="{Binding GroupFilter}"/>
+      <Button Grid.Column="4" Content="＋ Neue Aufgabe" Command="{Binding AddTaskCommand}"/>
     </Grid>
 
-    <ScrollViewer Grid.Row="2" Margin="16,0,16,16">
+    <ScrollViewer Grid.Row="1" Margin="16,10,16,16">
       <StackPanel>
         <ItemsControl ItemsSource="{Binding Tasks}">
           <ItemsControl.ItemTemplate>
@@ -46,11 +36,15 @@
                       <Run Text=" · "/>
                       <Run Text="{Binding GroupName}"/>
                     </TextBlock>
+                    <!-- Ist-Zeit vs. Schätzung (6.2.4) -->
+                    <TextBlock Text="{Binding ActualVsEstimateDisplay}" FontSize="11" Opacity="0.6"
+                               IsVisible="{Binding HasActualTime}"/>
                   </StackPanel>
                   <TextBlock Grid.Column="2" Text="{Binding DueDateDisplay}" VerticalAlignment="Center"
                              Margin="0,0,10,0" FontSize="12" Foreground="{Binding DueDateColorHex}"/>
                   <TextBlock Grid.Column="3" Text="{Binding EstimatedMinutesDisplay}"
-                             VerticalAlignment="Center" Opacity="0.6" FontSize="12" Margin="0,0,10,0"/>
+                             VerticalAlignment="Center" Opacity="0.6" FontSize="12" Margin="0,0,10,0"
+                             IsVisible="{Binding !HasActualTime}"/>
                   <Button Grid.Column="4" Content="Bearbeiten" FontSize="11" Padding="8,3" Margin="0,0,4,0"
                           Command="{Binding $parent[ItemsControl].((vm:WorkTaskListViewModel)DataContext).EditTaskCommand}"
                           CommandParameter="{Binding}"/>

LehrerApp.Desktop/Views/Workload/WorkloadView.axaml

@@ -0,0 +1,24 @@
+<UserControl xmlns="https://github.com/avaloniaui"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:vm="clr-namespace:LehrerApp.Desktop.ViewModels.Workload"
+             xmlns:views="clr-namespace:LehrerApp.Desktop.Views.Workload"
+             xmlns:shared="clr-namespace:LehrerApp.Desktop.Views.Shared"
+             x:Class="LehrerApp.Desktop.Views.Workload.WorkloadView"
+             x:DataType="vm:WorkloadViewModel">
+  <Grid RowDefinitions="Auto,*">
+    <Border Grid.Row="0" Padding="20,16"
+            BorderBrush="{DynamicResource SystemControlForegroundBaseLowBrush}"
+            BorderThickness="0,0,0,1">
+      <shared:PageHeader Title="Arbeitszeit" Subtitle="{Binding Tasks.CountSummary}"/>
+    </Border>
+
+    <TabbedPage Grid.Row="1" TabPlacement="Top" SelectedIndex="{Binding ActiveTabIndex}">
+      <ContentPage Header="Aufgaben">
+        <views:WorkTaskListView DataContext="{Binding Tasks}"/>
+      </ContentPage>
+      <ContentPage Header="Zeiterfassung">
+        <views:TimeTrackingView DataContext="{Binding TimeTracking}"/>
+      </ContentPage>
+    </TabbedPage>
+  </Grid>
+</UserControl>

LehrerApp.Desktop/Views/Workload/WorkloadView.axaml.cs

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

TODO.md

@@ -778,8 +778,9 @@ dadurch faktisch schon (Quick-Input-Dialog bzw. "Offene Entschuldigungen" im Das
 ## 6. Arbeitszeit & Aufgaben
 
 Modelle `WorkTask` und `TimeEntry` existieren, Repositories ebenfalls.
-Navigationspunkt "Arbeitszeit" zeigt inzwischen die Aufgabenverwaltung (6.1) statt eines
+Navigationspunkt "Arbeitszeit" zeigt inzwischen Aufgabenverwaltung (6.1) und Zeiterfassung (6.2)
-Placeholders; Zeiterfassung (6.2/6.3) ist noch offen.
+als zwei Tabs (`WorkloadViewModel`/`WorkloadView`, gleiches Container-Tab-Muster wie
+`GroupDetailViewModel`); nur die Monats-/Jahresauswertung (6.3) ist noch offen.
 
 ### 6.1 Aufgabenverwaltung
 - [x] **6.1.1** Aufgabenliste mit Filter nach Status, Kategorie, Gruppe und Fälligkeit —
@@ -799,10 +800,23 @@ Placeholders; Zeiterfassung (6.2/6.3) ist noch offen.
       auf `Conducted` (Anbindung an 1.1.3).
 
 ### 6.2 Zeiterfassung
-- [ ] **6.2.1** Timer starten/stoppen mit Zuordnung zu Aufgabe oder Kategorie.
+- [x] **6.2.1** Timer starten/stoppen mit Zuordnung zu Aufgabe oder Kategorie —
-- [ ] **6.2.2** Manuelle Nacherfassung eines Zeitblocks (Datum, Von–Bis oder Dauer).
+      `TimeTrackingViewModel`. Bewusst ohne live mitlaufende Sekundenanzeige (keine
-- [ ] **6.2.3** Wochenübersicht der erfassten Zeit, Summen je Kategorie.
+      `DispatcherTimer`-Kopplung in die ViewModel-Schicht); während der Timer läuft, zeigt
-- [ ] **6.2.4** Schätzung vs. tatsächliche Dauer je Aufgabe vergleichen.
+      "Läuft seit HH:mm Uhr" den Startzeitpunkt, die Dauer wird beim Stoppen aus der
+      Differenz berechnet (mind. 1 Minute).
+- [x] **6.2.2** Manuelle Nacherfassung eines Zeitblocks (Datum, Von–Bis oder Dauer) —
+      `AddTimeEntryDialog`: entweder Dauer direkt eintragen oder Von/Bis angeben (daraus wird
+      die Dauer berechnet); mindestens eines von beidem ist Pflicht.
+- [x] **6.2.3** Wochenübersicht der erfassten Zeit, Summen je Kategorie — Balken je Kategorie
+      (`CategoryWeekSummary`, `TimeEntry.Category` ist bewusst ein freier String statt
+      `TaskCategory`-Enum wie bei `WorkTask`, da das Domänenmodell das schon so vorgab; die
+      ComboBox schlägt trotzdem dieselben Kategorienamen vor). Nur die aktuelle Kalenderwoche,
+      keine Wochennavigation wie im Stundenplan — bei Bedarf später ergänzbar.
+- [x] **6.2.4** Schätzung vs. tatsächliche Dauer je Aufgabe vergleichen — direkt in der
+      Aufgabenliste (6.1.1) als "X / Y min erfasst", sobald mindestens ein verknüpfter
+      Zeiteintrag existiert; dafür braucht `WorkTaskListViewModel` jetzt zusätzlich
+      `ITimeEntryRepository`.
 
 ### 6.3 Auswertung
 - [ ] **6.3.1** Monats-/Jahresauswertung nach Kategorie und Gruppe (Diagramm + Tabelle).