feat(claude-do): [A4] WeeklyReport, DailyPrep und Planning-Aktionen auf OperationStatus umstellen

WeeklyReportModalViewModel.Generate, PrepPanelViewModel.PlanDayAsync und die beiden
Planning-Aktionen (QueuePlanningSubtasksAsync, FinalizePlanningSessionAsync) laufen jetzt
durch je eine OperationStatus + OperationIndicator statt handgebauter Spinner. Die beiden
Planning-Aktionen teilen sich eine Instanz, angezeigt im Tasks-Island-Header, weil sie aus
einem sofort schliessenden Kontextmenue ausgeloest werden und es keine dauerhafte
Pro-Zeilen-Flaeche gibt, an die ein Indikator gehaengt werden koennte.

src/ClaudeDo.Ui/ViewModels/Islands/PrepPanelViewModel.cs

@@ -3,6 +3,7 @@ using System.Text;
 using CommunityToolkit.Mvvm.ComponentModel;
 using CommunityToolkit.Mvvm.Input;
 using ClaudeDo.Ui.Helpers;
+using ClaudeDo.Ui.Localization;
 using ClaudeDo.Ui.Services;
 
 namespace ClaudeDo.Ui.ViewModels.Islands;
@@ -19,11 +20,23 @@ public sealed partial class PrepPanelViewModel : ViewModelBase, IDisposable
 
     [ObservableProperty] private bool _isPrepRunning;
 
+    // Covers the gap between the click and the worker's PrepStartedEvent broadcast — IsPrepRunning
+    // stays false until that event arrives, so without this the button click looks like a no-op.
+    public OperationStatus PrepOperation { get; } = new();
+
     public ObservableCollection<LogLineViewModel> PrepLog { get; } = new();
 
     public bool ShowPrepEmptyState => !IsPrepRunning && PrepLog.Count == 0;
 
-    partial void OnIsPrepRunningChanged(bool value) => OnPropertyChanged(nameof(ShowPrepEmptyState));
+    // The long-running broadcast-driven state (IsPrepRunning) and the click-to-event gap
+    // (PrepOperation.IsRunning) both need to block a second click.
+    public bool IsPlanDayEnabled => !IsPrepRunning && !PrepOperation.IsRunning;
+
+    partial void OnIsPrepRunningChanged(bool value)
+    {
+        OnPropertyChanged(nameof(ShowPrepEmptyState));
+        OnPropertyChanged(nameof(IsPlanDayEnabled));
+    }
 
     public PrepPanelViewModel(IWorkerClient worker)
     {
@@ -37,6 +50,15 @@ public sealed partial class PrepPanelViewModel : ViewModelBase, IDisposable
         _worker.PrepFinishedEvent += _onPrepFinishedHandler;
 
         PrepLog.CollectionChanged += (_, _) => OnPropertyChanged(nameof(ShowPrepEmptyState));
+
+        // OperationStatus is a nested ObservableObject — [NotifyCanExecuteChangedFor] can't see
+        // into it, so IsRunning changes are relayed by hand.
+        PrepOperation.PropertyChanged += (_, e) =>
+        {
+            if (e.PropertyName != nameof(OperationStatus.IsRunning)) return;
+            PlanDayCommand.NotifyCanExecuteChanged();
+            OnPropertyChanged(nameof(IsPlanDayEnabled));
+        };
     }
 
     public void Dispose()
@@ -46,9 +68,12 @@ public sealed partial class PrepPanelViewModel : ViewModelBase, IDisposable
         _worker.PrepFinishedEvent -= _onPrepFinishedHandler;
     }
 
-    [RelayCommand]
+    private bool CanPlanDay() => IsPlanDayEnabled;
+
+    [RelayCommand(CanExecute = nameof(CanPlanDay))]
     private async System.Threading.Tasks.Task PlanDayAsync()
     {
+        using var op = PrepOperation.Begin(Loc.T("ops.reports.runningDailyPrep"));
         try { await _worker.RunDailyPrepNowAsync(); }
         catch { }
     }