fix(ui): duplizierter Confirm-Dialog mit "Delete"-Knopf – zusammenfuehren und lokalisieren

F4: DetailsIslandView/TasksIslandView hatten je eine view-lokale Confirm/Error-Dialog-Kopie,
teils mit hartkodiertem "Delete"-Knopf fuer jede Aktion (inkl. der Stash+Merge-Bestaetigung,
die nichts loescht). Beide Kopien entfernt; DetailsIslandViewModel/TasksIslandViewModel routen
Confirm/Error jetzt durch den geteilten Dialogs-Seam (IDialogService, propagiert vom Shell wie
schon bei Lists/Tasks) statt ueber eine vom Code-behind gesetzte Func-Property.

IDialogService.ConfirmAsync bekommt einen optionalen confirmLabel-Parameter (Default: lokalisiertes
"Confirm"); nur die echten Delete-Aktionen (Task loeschen, abgeschlossene Tasks leeren) uebergeben
das lokalisierte "Delete"-Label.

F5: "Cancel"/"Confirm"/"Delete"/"OK" und die Titel "Confirm"/"Error" durch Loc.T mit neuen Keys
unter "dialog.*" ersetzt (en.json + de.json). Mission Controls eigene Dialog-Kopie bleibt bestehen
(eigenes Fenster, WindowDialogService ist an den Haupt-Owner gebunden) — nur ihre Labels wurden
lokalisiert.

Out of scope (siehe Task-Beschreibung): die Nachrichtentexte der Dialoge bleiben unlokalisiert.

tests/ClaudeDo.Ui.Tests/ViewModels/DetailsIslandDeleteTaskTests.cs

@@ -90,12 +90,12 @@ public class DetailsIslandDeleteTaskTests : IDisposable
         vm.DeleteFromList = _ => { deleteFromListCalled = true; return Task.CompletedTask; };
         var closed = false;
         vm.CloseDetail = () => closed = true;
-        string? reportedError = null;
-        vm.ShowErrorAsync = msg => { reportedError = msg; return Task.CompletedTask; };
+        var dialogs = new RecordingDialogService();
+        vm.Dialogs = dialogs;
 
         await vm.DeleteTaskCommand.ExecuteAsync(null);
 
-        Assert.Equal(fkMessage, reportedError);
+        Assert.Equal(fkMessage, dialogs.LastErrorMessage);
         Assert.False(deleteFromListCalled);
         Assert.False(closed);
     }
@@ -136,12 +136,12 @@ public class DetailsIslandDeleteTaskTests : IDisposable
         vm.DeleteFromList = _ => { deleteFromListCalled = true; return Task.CompletedTask; };
         var closed = false;
         vm.CloseDetail = () => closed = true;
-        string? reportedError = null;
-        vm.ShowErrorAsync = msg => { reportedError = msg; return Task.CompletedTask; };
+        var dialogs = new RecordingDialogService();
+        vm.Dialogs = dialogs;
 
         await vm.DeleteTaskCommand.ExecuteAsync(null);
 
-        Assert.Equal("Connection is not active.", reportedError);
+        Assert.Equal("Connection is not active.", dialogs.LastErrorMessage);
         Assert.False(deleteFromListCalled);
         Assert.False(closed);
     }

tests/ClaudeDo.Ui.Tests/ViewModels/DetailsIslandErrorFeedbackTests.cs

@@ -164,7 +164,7 @@ public class DetailsIslandErrorFeedbackTests : IDisposable
         var vm = BuildVm(worker);
         vm.Bind(new TaskRowViewModel { Id = "task-reset-throw", Status = TaskStatus.Failed });
         vm.Monitor.ApplyState(TaskStatus.Failed);
-        vm.ConfirmAsync = _ => Task.FromResult(true);
+        vm.Dialogs = new RecordingDialogService { ConfirmResult = true };
 
         string? reportedError = null;
         vm.ErrorReported += msg => reportedError = msg;

tests/ClaudeDo.Ui.Tests/ViewModels/DetailsIslandReviewActionsTests.cs

@@ -153,12 +153,12 @@ public class DetailsIslandReviewActionsTests : IDisposable
         vm.Bind(new TaskRowViewModel { Id = "task-err-1", Status = TaskStatus.WaitingForReview });
         vm.Monitor.ApplyState(TaskStatus.WaitingForReview);
 
-        string? reportedError = null;
-        vm.ShowErrorAsync = msg => { reportedError = msg; return Task.CompletedTask; };
+        var dialogs = new RecordingDialogService();
+        vm.Dialogs = dialogs;
 
         await vm.ApproveReviewCommand.ExecuteAsync(null);
 
-        Assert.Equal(worker.ExceptionMessage, reportedError);
+        Assert.Equal(worker.ExceptionMessage, dialogs.LastErrorMessage);
         Assert.False(vm.ApproveOp.IsRunning);
         Assert.True(vm.ApproveReviewCommand.CanExecute(null));
     }

tests/ClaudeDo.Ui.Tests/ViewModels/ListsIslandCreateListCancelTests.cs

@@ -62,7 +62,7 @@ public class ListsIslandCreateListCancelTests : IDisposable
         public Task ShowWorkerConnectionAsync(WorkerConnectionModalViewModel vm) => throw new NotImplementedException();
         public Task ShowConflictResolverAsync(ConflictResolverViewModel vm) => throw new NotImplementedException();
         public Task ShowLogVisualizerAsync(LogVisualizerViewModel vm) => throw new NotImplementedException();
-        public Task<bool> ConfirmAsync(string message) => Task.FromResult(true);
+        public Task<bool> ConfirmAsync(string message, string? confirmLabel = null) => Task.FromResult(true);
         public Task ShowErrorAsync(string message) => Task.CompletedTask;
         public void ShowMissionControl(MissionControlViewModel vm) => throw new NotImplementedException();
         public void ShowCheatSheets(CheatSheetsViewModel vm) => throw new NotImplementedException();

tests/ClaudeDo.Ui.Tests/ViewModels/TasksIslandMoveToListTests.cs

@@ -43,7 +43,7 @@ public class TasksIslandMoveToListTests : IDisposable
         public int ConfirmCalls;
         public string? LastMessage;
 
-        public Task<bool> ConfirmAsync(string message)
+        public Task<bool> ConfirmAsync(string message, string? confirmLabel = null)
         {
             ConfirmCalls++;
             LastMessage = message;