fix(worker-client): stop swallowing mutating hub call failures

TryInvokeAsync catches every exception and returns null, which is fine
for read-only calls but hid real HubException reasons behind a generic
"offline" message for the 7 mutating call sites (RestoreDefaultAgents,
UpsertPrimeSchedule, AddDailyNote, CleanupFinishedWorktrees,
ResetAllWorktrees, ForceRemoveWorktree, BuildPlanningIntegrationBranch)
— the same bug class fixed for ApproveReview in e1807fd. Each of the 22
TryInvokeAsync call sites was audited; the 15 read-only ones are left
unchanged (empty/offline is the right display). For the 7 switched to
a direct hub invoke, every caller was checked and, where it had no
catch, one was added so the exception surfaces (StatusMessage,
ShowErrorAsync/CombinedWarning) instead of crashing.

src/ClaudeDo.Localization/locales/de.json

@@ -543,7 +543,7 @@
     "taskRow": { "createdPrefix": "Erstellt {0}", "stepsText": "{0}/{1} Schritte" },
     "tasksIsland": { "completedHeader": "ABGESCHLOSSEN", "completedHeaderCount": "ABGESCHLOSSEN · {0}", "planningOpenFailed": "Planungssitzung konnte nicht geöffnet werden: {0}", "planningResumeFailed": "Planungssitzung konnte nicht fortgesetzt werden: {0}", "pickUpInTerminalFailed": "Im Terminal fortsetzen fehlgeschlagen: {0}", "approveFailed": "Genehmigen & Mergen fehlgeschlagen: {0}" },
     "diff": { "loadFailed": "Diff konnte nicht geladen werden: {0}", "noChanges": "Keine Änderungen anzuzeigen.", "unavailable": "Diff nicht mehr verfügbar — Commit-Bereich unvollständig." },
-    "planningDiff": { "hubError": "Kombinierte Vorschau konnte nicht erstellt werden (Hub-Fehler).", "conflict": "Kombinierte Vorschau nicht möglich: Teilaufgabe {0} steht im Konflikt mit einer früheren Teilaufgabe ({1} Dateien)." },
+    "planningDiff": { "hubError": "Kombinierte Vorschau konnte nicht erstellt werden (Hub-Fehler).", "conflict": "Kombinierte Vorschau nicht möglich: Teilaufgabe {0} steht im Konflikt mit einer früheren Teilaufgabe ({1} Dateien).", "buildFailed": "Kombinierte Vorschau konnte nicht erstellt werden: {0}" },
     "merge": { "commitMessage": "Merge-Aufgabe: {0}", "workerOfflineBranches": "Worker offline — Branches können nicht aufgelistet werden.", "loadBranchesFailed": "Branches konnten nicht geladen werden: {0}", "merged": "Zusammengeführt.", "conflict": "Merge-Konflikt — Ziel-Branch wiederhergestellt. Manuell oder über Fortsetzen lösen, dann erneut versuchen.", "blocked": "Blockiert: {0}", "unknownStatus": "Unbekannter Status: {0}", "mergeFailed": "Merge fehlgeschlagen: {0}" },
     "conflictResolution": { "vsCodeError": "VS Code konnte nicht gestartet werden: {0}. Die Pfade sind oben aufgeführt — kopiere sie manuell.", "subtaskPrefix": "Konflikte in Teilaufgabe: {0}", "targetPrefix": "Zusammenführen in: {0}" },
     "settingsModal": { "workerOffline": "Worker offline — Einstellungen schreibgeschützt.", "saveFailed": "Speichern fehlgeschlagen: {0}" },
@@ -551,8 +551,8 @@
     "weeklyReport": { "invalidRange": "Ungültiger Datumsbereich.", "generating": "Bericht wird erstellt…", "error": "Fehler: {0}" },
     "filesTab": { "workerOffline": "Worker offline.", "noneBundled": "Keine Standard-Agenten mitgeliefert.", "allPresent": "Alle Standard-Agenten bereits vorhanden.", "restored": "{0} Standard-Agent(en) wiederhergestellt.", "restoreFailed": "Wiederherstellung fehlgeschlagen: {0}", "openFailed": "Öffnen fehlgeschlagen: {0}" },
     "sessionSkillsTab": { "installed": "Installiert: {0}", "installFailed": "Installation fehlgeschlagen: {0}", "updated": "Aktualisiert.", "updateFailed": "Aktualisierung fehlgeschlagen: {0}", "removed": "Entfernt.", "removeFailed": "Entfernen fehlgeschlagen: {0}" },
-    "worktreesTab": { "workerOffline": "Worker offline.", "removed": "{0} Worktree(s) entfernt.", "blocked": "Zwangsentfernung nicht möglich: {0} Aufgabe(n) laufen noch. Brich sie zuerst ab.", "removedFrom": "{0} Worktree(s) von {1} Aufgabe(n) entfernt." },
-    "worktreesOverview": { "titleAll": "Worktrees", "titleList": "Worktrees — {0}", "listFallback": "Liste", "cleanupFailed": "Aufräumen fehlgeschlagen.", "removed": "{0} Worktree(s) entfernt.", "discardFailed": "Worktree konnte nicht verworfen werden.", "keepFailed": "Worktree konnte nicht behalten werden.", "cannotForceRunning": "Eine laufende Aufgabe kann nicht zwangsweise entfernt werden.", "forceRemoveFailed": "Zwangsentfernung fehlgeschlagen.", "batchProgress": "Merge {0}/{1}…", "batchDone": "{0} gemergt, {1} zu lösen." },
+    "worktreesTab": { "workerOffline": "Worker offline.", "removed": "{0} Worktree(s) entfernt.", "blocked": "Zwangsentfernung nicht möglich: {0} Aufgabe(n) laufen noch. Brich sie zuerst ab.", "removedFrom": "{0} Worktree(s) von {1} Aufgabe(n) entfernt.", "cleanupFailed": "Aufräumen fehlgeschlagen: {0}", "resetFailed": "Zurücksetzen fehlgeschlagen: {0}" },
+    "worktreesOverview": { "titleAll": "Worktrees", "titleList": "Worktrees — {0}", "listFallback": "Liste", "cleanupFailed": "Aufräumen fehlgeschlagen.", "cleanupFailedDetailed": "Aufräumen fehlgeschlagen: {0}", "removed": "{0} Worktree(s) entfernt.", "discardFailed": "Worktree konnte nicht verworfen werden.", "keepFailed": "Worktree konnte nicht behalten werden.", "cannotForceRunning": "Eine laufende Aufgabe kann nicht zwangsweise entfernt werden.", "forceRemoveFailed": "Zwangsentfernung fehlgeschlagen.", "forceRemoveFailedDetailed": "Zwangsentfernung fehlgeschlagen: {0}", "batchProgress": "Merge {0}/{1}…", "batchDone": "{0} gemergt, {1} zu lösen." },
     "listSettings": { "untitled": "Unbenannt" },
     "lists": { "localSuffix": "{0} / lokal", "smartMyDay": "Mein Tag", "smartImportant": "Wichtig", "smartPlanned": "Geplant", "virtualQueue": "Warteschlange", "virtualRunning": "Läuft", "virtualReview": "Prüfung", "newList": "Neue Liste" }
   }

src/ClaudeDo.Localization/locales/en.json

@@ -543,7 +543,7 @@
     "taskRow": { "createdPrefix": "Created {0}", "stepsText": "{0}/{1} steps" },
     "tasksIsland": { "completedHeader": "COMPLETED", "completedHeaderCount": "COMPLETED · {0}", "planningOpenFailed": "Couldn't open planning session: {0}", "planningResumeFailed": "Couldn't resume planning session: {0}", "pickUpInTerminalFailed": "Pick up in terminal failed: {0}", "approveFailed": "Approve & merge failed: {0}" },
     "diff": { "loadFailed": "Failed to load diff: {0}", "noChanges": "No changes to show.", "unavailable": "Diff no longer available — commit range incomplete." },
-    "planningDiff": { "hubError": "Could not build combined preview (hub error).", "conflict": "Cannot build combined preview: subtask {0} conflicts with an earlier subtask ({1} files)." },
+    "planningDiff": { "hubError": "Could not build combined preview (hub error).", "conflict": "Cannot build combined preview: subtask {0} conflicts with an earlier subtask ({1} files).", "buildFailed": "Could not build combined preview: {0}" },
     "merge": { "commitMessage": "Merge task: {0}", "workerOfflineBranches": "Worker offline — cannot list branches.", "loadBranchesFailed": "Failed to load branches: {0}", "merged": "Merged.", "conflict": "Merge conflict — target branch restored. Resolve manually or via Continue, then retry.", "blocked": "Blocked: {0}", "unknownStatus": "Unknown status: {0}", "mergeFailed": "Merge failed: {0}" },
     "conflictResolution": { "vsCodeError": "Could not launch VS Code: {0}. Paths are listed above — copy them manually.", "subtaskPrefix": "Conflicts in subtask: {0}", "targetPrefix": "Merging into: {0}" },
     "settingsModal": { "workerOffline": "Worker offline — settings read-only.", "saveFailed": "Save failed: {0}" },
@@ -551,8 +551,8 @@
     "weeklyReport": { "invalidRange": "Invalid date range.", "generating": "Generating report…", "error": "Error: {0}" },
     "filesTab": { "workerOffline": "Worker offline.", "noneBundled": "No default agents bundled.", "allPresent": "All default agents already present.", "restored": "Restored {0} default agent(s).", "restoreFailed": "Restore failed: {0}", "openFailed": "Open failed: {0}" },
     "sessionSkillsTab": { "installed": "Installed: {0}", "installFailed": "Install failed: {0}", "updated": "Updated.", "updateFailed": "Update failed: {0}", "removed": "Removed.", "removeFailed": "Remove failed: {0}" },
-    "worktreesTab": { "workerOffline": "Worker offline.", "removed": "Removed {0} worktree(s).", "blocked": "Cannot force-remove: {0} task(s) still running. Cancel them first.", "removedFrom": "Removed {0} worktree(s) from {1} task(s)." },
-    "worktreesOverview": { "titleAll": "Worktrees", "titleList": "Worktrees — {0}", "listFallback": "list", "cleanupFailed": "Cleanup failed.", "removed": "Removed {0} worktree(s).", "discardFailed": "Failed to discard worktree.", "keepFailed": "Failed to keep worktree.", "cannotForceRunning": "Cannot force-remove a running task.", "forceRemoveFailed": "Force remove failed.", "batchProgress": "Merging {0}/{1}…", "batchDone": "Merged {0}, {1} need resolution." },
+    "worktreesTab": { "workerOffline": "Worker offline.", "removed": "Removed {0} worktree(s).", "blocked": "Cannot force-remove: {0} task(s) still running. Cancel them first.", "removedFrom": "Removed {0} worktree(s) from {1} task(s).", "cleanupFailed": "Cleanup failed: {0}", "resetFailed": "Reset failed: {0}" },
+    "worktreesOverview": { "titleAll": "Worktrees", "titleList": "Worktrees — {0}", "listFallback": "list", "cleanupFailed": "Cleanup failed.", "cleanupFailedDetailed": "Cleanup failed: {0}", "removed": "Removed {0} worktree(s).", "discardFailed": "Failed to discard worktree.", "keepFailed": "Failed to keep worktree.", "cannotForceRunning": "Cannot force-remove a running task.", "forceRemoveFailed": "Force remove failed.", "forceRemoveFailedDetailed": "Force remove failed: {0}", "batchProgress": "Merging {0}/{1}…", "batchDone": "Merged {0}, {1} need resolution." },
     "listSettings": { "untitled": "Untitled" },
     "lists": { "localSuffix": "{0} / local", "smartMyDay": "My Day", "smartImportant": "Important", "smartPlanned": "Planned", "virtualQueue": "Queue", "virtualRunning": "Running", "virtualReview": "Review", "newList": "New list" }
   }

src/ClaudeDo.Ui/Services/WorkerClient.cs

@@ -329,8 +329,8 @@ public partial class WorkerClient : ObservableObject, IAsyncDisposable, IWorkerC
         await _hub.InvokeAsync("RefreshAgents");
     }
 
-    public Task<SeedResultDto?> RestoreDefaultAgentsAsync()
-        => TryInvokeAsync<SeedResultDto>("RestoreDefaultAgents");
+    public async Task<SeedResultDto?> RestoreDefaultAgentsAsync()
+        => await _hub.InvokeAsync<SeedResultDto>("RestoreDefaultAgents");
 
     private async Task SeedActiveTasksAsync()
     {
@@ -372,8 +372,8 @@ public partial class WorkerClient : ObservableObject, IAsyncDisposable, IWorkerC
     public async Task<List<PrimeScheduleDto>> GetPrimeSchedulesAsync()
         => await TryInvokeAsync<List<PrimeScheduleDto>>("ListPrimeSchedules") ?? new List<PrimeScheduleDto>();
 
-    public Task<PrimeScheduleDto?> UpsertPrimeScheduleAsync(PrimeScheduleDto dto)
-        => TryInvokeAsync<PrimeScheduleDto>("UpsertPrimeSchedule", dto);
+    public async Task<PrimeScheduleDto?> UpsertPrimeScheduleAsync(PrimeScheduleDto dto)
+        => await _hub.InvokeAsync<PrimeScheduleDto>("UpsertPrimeSchedule", dto);
 
     public async Task DeletePrimeScheduleAsync(Guid id)
     {
@@ -400,8 +400,8 @@ public partial class WorkerClient : ObservableObject, IAsyncDisposable, IWorkerC
     public async Task<List<DailyNoteDto>> GetDailyNotesAsync(DateOnly day)
         => await TryInvokeAsync<List<DailyNoteDto>>("GetDailyNotes", IsoDay(day)) ?? new List<DailyNoteDto>();
 
-    public Task<DailyNoteDto?> AddDailyNoteAsync(DateOnly day, string text)
-        => TryInvokeAsync<DailyNoteDto>("AddDailyNote", IsoDay(day), text);
+    public async Task<DailyNoteDto?> AddDailyNoteAsync(DateOnly day, string text)
+        => await _hub.InvokeAsync<DailyNoteDto>("AddDailyNote", IsoDay(day), text);
 
     public async Task UpdateDailyNoteAsync(string id, string text)
         => await _hub.InvokeAsync("UpdateDailyNote", id, text);
@@ -474,11 +474,11 @@ public partial class WorkerClient : ObservableObject, IAsyncDisposable, IWorkerC
         await _hub.InvokeAsync("CancelReview", taskId);
     }
 
-    public Task<WorktreeCleanupDto?> CleanupFinishedWorktreesAsync(string? listId = null)
-        => TryInvokeAsync<WorktreeCleanupDto>("CleanupFinishedWorktrees", listId);
+    public async Task<WorktreeCleanupDto?> CleanupFinishedWorktreesAsync(string? listId = null)
+        => await _hub.InvokeAsync<WorktreeCleanupDto>("CleanupFinishedWorktrees", listId);
 
-    public Task<WorktreeResetDto?> ResetAllWorktreesAsync()
-        => TryInvokeAsync<WorktreeResetDto>("ResetAllWorktrees");
+    public async Task<WorktreeResetDto?> ResetAllWorktreesAsync()
+        => await _hub.InvokeAsync<WorktreeResetDto>("ResetAllWorktrees");
 
     public async Task<List<WorktreeOverviewDto>> GetWorktreesOverviewAsync(string? listId)
         => await TryInvokeAsync<List<WorktreeOverviewDto>>("GetWorktreesOverview", listId)
@@ -501,8 +501,8 @@ public partial class WorkerClient : ObservableObject, IAsyncDisposable, IWorkerC
         }
     }
 
-    public Task<ForceRemoveResultDto?> ForceRemoveWorktreeAsync(string taskId)
-        => TryInvokeAsync<ForceRemoveResultDto>("ForceRemoveWorktree", taskId);
+    public async Task<ForceRemoveResultDto?> ForceRemoveWorktreeAsync(string taskId)
+        => await _hub.InvokeAsync<ForceRemoveResultDto>("ForceRemoveWorktree", taskId);
 
     public async Task<PlanningSessionStartInfo> StartPlanningSessionAsync(string taskId, CancellationToken ct = default)
         => await _hub.InvokeAsync<PlanningSessionStartInfo>("StartPlanningSessionAsync", taskId, ct);
@@ -543,8 +543,8 @@ public partial class WorkerClient : ObservableObject, IAsyncDisposable, IWorkerC
     public async Task<IReadOnlyList<SubtaskDiffDto>> GetPlanningAggregateAsync(string planningTaskId)
         => await TryInvokeAsync<List<SubtaskDiffDto>>("GetPlanningAggregate", planningTaskId) ?? [];
 
-    public Task<CombinedDiffResultDto?> BuildPlanningIntegrationBranchAsync(string planningTaskId, string targetBranch)
-        => TryInvokeAsync<CombinedDiffResultDto>("BuildPlanningIntegrationBranch", planningTaskId, targetBranch);
+    public async Task<CombinedDiffResultDto?> BuildPlanningIntegrationBranchAsync(string planningTaskId, string targetBranch)
+        => await _hub.InvokeAsync<CombinedDiffResultDto>("BuildPlanningIntegrationBranch", planningTaskId, targetBranch);
 
     public async Task ContinuePlanningMergeAsync(string planningTaskId)
     {

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

@@ -311,6 +311,7 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
         Prep = new PrepPanelViewModel(worker);
 
         Notes = new NotesEditorViewModel(_notesApi);
+        Notes.ErrorReported += msg => { if (ShowErrorAsync is not null) _ = ShowErrorAsync(msg); };
         Subtasks.CollectionChanged += (_, _) => NotifyStepsChanged();
         Subtasks.CollectionChanged += (_, _) => Merge.SyncChildOutcomes(HasChildOutcomes, Subtasks.Count);
         Attachments.CollectionChanged += (_, _) => OnPropertyChanged(nameof(FilesBadge));

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

@@ -24,6 +24,9 @@ public sealed partial class NotesEditorViewModel : ViewModelBase
 
     public NotesEditorViewModel(INotesApi api) => _api = api;
 
+    // Raised when a worker call fails so the host VM can surface it (e.g. via ShowErrorAsync).
+    public event Action<string>? ErrorReported;
+
     public ObservableCollection<NoteBulletViewModel> Bullets { get; } = new();
 
     [ObservableProperty] private DateOnly _currentDay = DateOnly.FromDateTime(DateTime.Today);
@@ -55,9 +58,16 @@ public sealed partial class NotesEditorViewModel : ViewModelBase
     {
         var text = NewBulletText.Trim();
         if (text.Length == 0) return;
-        var dto = await _api.AddAsync(CurrentDay, text);
-        if (dto is not null) Bullets.Add(MakeBullet(dto.Id, dto.Text));
-        NewBulletText = "";
+        try
+        {
+            var dto = await _api.AddAsync(CurrentDay, text);
+            if (dto is not null) Bullets.Add(MakeBullet(dto.Id, dto.Text));
+            NewBulletText = "";
+        }
+        catch (Exception ex)
+        {
+            ErrorReported?.Invoke(ex.Message);
+        }
     }
 
     [RelayCommand] private Task PrevDay() => LoadDayAsync(CurrentDay.AddDays(-1));

src/ClaudeDo.Ui/ViewModels/Modals/DiffViewerViewModel.cs

@@ -197,6 +197,11 @@ public sealed partial class DiffViewerViewModel : ViewModelBase
                     DisplayedDiff = "";
                 }
             }
+            catch (Exception ex)
+            {
+                DisplayedDiff = "";
+                CombinedWarning = Loc.T("vm.planningDiff.buildFailed", ex.Message);
+            }
             finally
             {
                 IsLoadingCombined = false;

src/ClaudeDo.Ui/ViewModels/Modals/Settings/WorktreesSettingsTabViewModel.cs

@@ -46,6 +46,7 @@ public sealed partial class WorktreesSettingsTabViewModel : ViewModelBase
             var r = await _worker.CleanupFinishedWorktreesAsync();
             StatusMessage = r is null ? Loc.T("vm.worktreesTab.workerOffline") : Loc.T("vm.worktreesTab.removed", r.Removed);
         }
+        catch (Exception ex) { StatusMessage = Loc.T("vm.worktreesTab.cleanupFailed", ex.Message); }
         finally { IsBusy = false; }
     }
 
@@ -63,6 +64,7 @@ public sealed partial class WorktreesSettingsTabViewModel : ViewModelBase
             else if (r.Blocked) StatusMessage = Loc.T("vm.worktreesTab.blocked", r.RunningTasks);
             else StatusMessage = Loc.T("vm.worktreesTab.removedFrom", r.Removed, r.TasksAffected);
         }
+        catch (Exception ex) { StatusMessage = Loc.T("vm.worktreesTab.resetFailed", ex.Message); }
         finally { IsBusy = false; }
     }
 }

src/ClaudeDo.Ui/ViewModels/Modals/WorktreesOverviewModalViewModel.cs

@@ -174,6 +174,7 @@ public sealed partial class WorktreesOverviewModalViewModel : ViewModelBase
             StatusMessage = result is null ? Loc.T("vm.worktreesOverview.cleanupFailed") : Loc.T("vm.worktreesOverview.removed", result.Removed);
             await LoadAsync();
         }
+        catch (Exception ex) { StatusMessage = Loc.T("vm.worktreesOverview.cleanupFailedDetailed", ex.Message); }
         finally { IsBusy = false; }
     }
 
@@ -241,7 +242,16 @@ public sealed partial class WorktreesOverviewModalViewModel : ViewModelBase
         if (row.IsRunning) { StatusMessage = Loc.T("vm.worktreesOverview.cannotForceRunning"); return; }
         if (ConfirmAction is not null && !await ConfirmAction($"Force remove worktree for '{row.TaskTitle}'? This deletes the directory and branch.")) return;
 
-        var result = await _worker.ForceRemoveWorktreeAsync(row.TaskId);
+        ForceRemoveResultDto? result;
+        try
+        {
+            result = await _worker.ForceRemoveWorktreeAsync(row.TaskId);
+        }
+        catch (Exception ex)
+        {
+            StatusMessage = Loc.T("vm.worktreesOverview.forceRemoveFailedDetailed", ex.Message);
+            return;
+        }
         if (result is null || !result.Removed)
         {
             StatusMessage = result?.Reason ?? Loc.T("vm.worktreesOverview.forceRemoveFailed");

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

@@ -21,11 +21,14 @@ public class DiffViewerViewModelTests
     {
         public IReadOnlyList<SubtaskDiffDto> AggregateResult { get; set; } = Array.Empty<SubtaskDiffDto>();
         public CombinedDiffResultDto? CombinedResult { get; set; }
+        public string? CombinedException { get; set; }
 
         public override Task<IReadOnlyList<SubtaskDiffDto>> GetPlanningAggregateAsync(string planningTaskId) =>
             Task.FromResult(AggregateResult);
         public override Task<CombinedDiffResultDto?> BuildPlanningIntegrationBranchAsync(string planningTaskId, string targetBranch) =>
-            Task.FromResult(CombinedResult);
+            CombinedException is not null
+                ? throw new Exception(CombinedException)
+                : Task.FromResult(CombinedResult);
     }
 
     // ── Files mode: commit-range guards (ported from DiffModal) ──
@@ -193,4 +196,26 @@ public class DiffViewerViewModelTests
         Assert.NotNull(vm.CombinedWarning);
         Assert.NotEmpty(vm.CombinedWarning!);
     }
+
+    [Fact]
+    public async Task Planning_ToggleCombined_WhenWorkerThrows_ShowsExceptionMessage()
+    {
+        var fake = new FakePlanningWorker
+        {
+            AggregateResult = new[] { new SubtaskDiffDto("s1", "First", "b1", "base1", "head1", null, "DIFF-A") },
+            CombinedException = "planning task not found",
+        };
+        var vm = new DiffViewerViewModel(null!, fake);
+        vm.ConfigurePlanning("plan-1", "main");
+        await vm.LoadAsync();
+
+        vm.IsCombinedMode = true;
+
+        var deadline = DateTime.UtcNow.AddSeconds(5);
+        while (DateTime.UtcNow < deadline && vm.IsLoadingCombined) await Task.Delay(10);
+
+        Assert.NotNull(vm.CombinedWarning);
+        Assert.Contains("planning task not found", vm.CombinedWarning);
+        Assert.Equal("", vm.DisplayedDiff);
+    }
 }

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

@@ -0,0 +1,38 @@
+using System.IO;
+using ClaudeDo.Localization;
+using ClaudeDo.Ui.Localization;
+using ClaudeDo.Ui.Services;
+using ClaudeDo.Ui.ViewModels.Modals.Settings;
+
+namespace ClaudeDo.Ui.Tests.ViewModels;
+
+public class FilesSettingsTabViewModelTests
+{
+    public FilesSettingsTabViewModelTests()
+    {
+        var dir = AppContext.BaseDirectory;
+        while (dir is not null && !Directory.Exists(Path.Combine(dir, "src", "ClaudeDo.Localization", "locales")))
+            dir = Path.GetDirectoryName(dir);
+        Loc.Current = new Localizer(
+            LocaleStore.Load(Path.Combine(dir!, "src", "ClaudeDo.Localization", "locales")), "en");
+    }
+
+    private sealed class ThrowingWorker : StubWorkerClient
+    {
+        public string ExceptionMessage { get; init; } = "permission denied copying agent files";
+        public override Task<SeedResultDto?> RestoreDefaultAgentsAsync() =>
+            throw new Exception(ExceptionMessage);
+    }
+
+    [Fact]
+    public async Task RestoreDefaultAgents_WhenWorkerThrows_ShowsExceptionMessage_NotGenericOffline()
+    {
+        var worker = new ThrowingWorker();
+        var vm = new FilesSettingsTabViewModel(worker);
+
+        await vm.RestoreDefaultAgentsCommand.ExecuteAsync(null);
+
+        Assert.Contains(worker.ExceptionMessage, vm.StatusMessage);
+        Assert.False(vm.IsBusy);
+    }
+}

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

@@ -27,6 +27,33 @@ public class NotesEditorViewModelTests
         public Task DeleteAsync(string id) { Store.RemoveAll(n => n.Id == id); return Task.CompletedTask; }
     }
 
+    private sealed class ThrowingNotes : INotesApi
+    {
+        public string ExceptionMessage { get; init; } = "worker offline";
+        public Task<List<DailyNoteDto>> ListAsync(DateOnly day) => Task.FromResult(new List<DailyNoteDto>());
+        public Task<DailyNoteDto?> AddAsync(DateOnly day, string text) => throw new Exception(ExceptionMessage);
+        public Task UpdateAsync(string id, string text) => Task.CompletedTask;
+        public Task DeleteAsync(string id) => Task.CompletedTask;
+    }
+
+    [Fact]
+    public async Task AddBullet_WhenApiThrows_RaisesErrorReported_AndKeepsDraftText()
+    {
+        var api = new ThrowingNotes();
+        var vm = new NotesEditorViewModel(api);
+        await vm.LoadDayAsync(new DateOnly(2026, 6, 1));
+
+        string? reportedError = null;
+        vm.ErrorReported += msg => reportedError = msg;
+
+        vm.NewBulletText = "Standup vorbereitet";
+        await vm.AddBulletCommand.ExecuteAsync(null);
+
+        Assert.Equal(api.ExceptionMessage, reportedError);
+        Assert.Empty(vm.Bullets);
+        Assert.Equal("Standup vorbereitet", vm.NewBulletText);
+    }
+
     [Fact]
     public async Task AddBullet_PersistsAndAppears_ForCurrentDay()
     {

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

@@ -19,6 +19,14 @@ public class PrimeClaudeTabViewModelTests
         public Task DeleteAsync(Guid id) { Deletes.Add(id); return Task.CompletedTask; }
     }
 
+    private sealed class ThrowingApi : IPrimeScheduleApi
+    {
+        public string ExceptionMessage { get; init; } = "worker offline";
+        public Task<List<PrimeScheduleDto>> ListAsync() => Task.FromResult(new List<PrimeScheduleDto>());
+        public Task<PrimeScheduleDto?> UpsertAsync(PrimeScheduleDto dto) => throw new Exception(ExceptionMessage);
+        public Task DeleteAsync(Guid id) => Task.CompletedTask;
+    }
+
     private static PrimeScheduleDto Dto(Guid id, int days, TimeSpan time) =>
         new(id, days, time, true, null, null);
 
@@ -93,4 +101,19 @@ public class PrimeClaudeTabViewModelTests
         vm.AddScheduleCommand.Execute(null);
         Assert.Null(vm.Validate());
     }
+
+    // SettingsModalViewModel.Save() is the only place that catches Prime.SaveAsync's
+    // failures (via a try/catch around the whole settings save) and surfaces them as
+    // "Save failed: {message}". For that to work, SaveAsync must propagate the worker's
+    // exception rather than swallow it.
+    [Fact]
+    public async Task Save_WhenApiThrows_PropagatesException()
+    {
+        var api = new ThrowingApi();
+        var vm = new PrimeClaudeTabViewModel(api);
+        vm.AddScheduleCommand.Execute(null);
+
+        var ex = await Assert.ThrowsAsync<Exception>(() => vm.SaveAsync());
+        Assert.Equal(api.ExceptionMessage, ex.Message);
+    }
 }

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

@@ -0,0 +1,65 @@
+using System.IO;
+using ClaudeDo.Localization;
+using ClaudeDo.Ui.Localization;
+using ClaudeDo.Ui.Services;
+using ClaudeDo.Ui.ViewModels.Modals;
+
+namespace ClaudeDo.Ui.Tests.ViewModels;
+
+public class WorktreesOverviewModalErrorTests
+{
+    public WorktreesOverviewModalErrorTests()
+    {
+        var dir = AppContext.BaseDirectory;
+        while (dir is not null && !Directory.Exists(Path.Combine(dir, "src", "ClaudeDo.Localization", "locales")))
+            dir = Path.GetDirectoryName(dir);
+        Loc.Current = new Localizer(
+            LocaleStore.Load(Path.Combine(dir!, "src", "ClaudeDo.Localization", "locales")), "en");
+    }
+
+    private sealed class ThrowingWorker : StubWorkerClient
+    {
+        public string ExceptionMessage { get; init; } = "worktree is locked by another process";
+        public override Task<WorktreeCleanupDto?> CleanupFinishedWorktreesAsync(string? listId = null) =>
+            throw new Exception(ExceptionMessage);
+        public override Task<ForceRemoveResultDto?> ForceRemoveWorktreeAsync(string taskId) =>
+            throw new Exception(ExceptionMessage);
+    }
+
+    private static WorktreesOverviewModalViewModel NewVm(ThrowingWorker worker) =>
+        new(worker, () => null!, new MergeCoordinator());
+
+    [Fact]
+    public async Task CleanupFinished_WhenWorkerThrows_ShowsExceptionMessage()
+    {
+        var worker = new ThrowingWorker();
+        var vm = NewVm(worker);
+
+        await vm.CleanupFinishedCommand.ExecuteAsync(null);
+
+        Assert.NotNull(vm.StatusMessage);
+        Assert.Contains(worker.ExceptionMessage, vm.StatusMessage);
+        Assert.False(vm.IsBusy);
+    }
+
+    [Fact]
+    public async Task ForceRemove_WhenWorkerThrows_ShowsExceptionMessage_AndKeepsRow()
+    {
+        var worker = new ThrowingWorker();
+        var vm = NewVm(worker);
+        var row = new WorktreeOverviewRowViewModel
+        {
+            TaskId = "task-1",
+            TaskTitle = "Task 1",
+            TaskStatus = ClaudeDo.Data.Models.TaskStatus.Idle,
+            State = ClaudeDo.Data.Models.WorktreeState.Active,
+        };
+        vm.AddRowForTest(row);
+
+        await vm.ForceRemoveCommand.ExecuteAsync(row);
+
+        Assert.NotNull(vm.StatusMessage);
+        Assert.Contains(worker.ExceptionMessage, vm.StatusMessage);
+        Assert.Contains(row, vm.Rows);
+    }
+}

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

@@ -0,0 +1,53 @@
+using System.IO;
+using ClaudeDo.Localization;
+using ClaudeDo.Ui.Localization;
+using ClaudeDo.Ui.Services;
+using ClaudeDo.Ui.ViewModels.Modals.Settings;
+
+namespace ClaudeDo.Ui.Tests.ViewModels;
+
+public class WorktreesSettingsTabViewModelTests
+{
+    public WorktreesSettingsTabViewModelTests()
+    {
+        var dir = AppContext.BaseDirectory;
+        while (dir is not null && !Directory.Exists(Path.Combine(dir, "src", "ClaudeDo.Localization", "locales")))
+            dir = Path.GetDirectoryName(dir);
+        Loc.Current = new Localizer(
+            LocaleStore.Load(Path.Combine(dir!, "src", "ClaudeDo.Localization", "locales")), "en");
+    }
+
+    private sealed class ThrowingWorker : StubWorkerClient
+    {
+        public string ExceptionMessage { get; init; } = "disk full";
+        public override Task<WorktreeCleanupDto?> CleanupFinishedWorktreesAsync(string? listId = null) =>
+            throw new Exception(ExceptionMessage);
+        public override Task<WorktreeResetDto?> ResetAllWorktreesAsync() =>
+            throw new Exception(ExceptionMessage);
+    }
+
+    [Fact]
+    public async Task CleanupWorktrees_WhenWorkerThrows_ShowsExceptionMessage()
+    {
+        var worker = new ThrowingWorker();
+        var vm = new WorktreesSettingsTabViewModel(worker);
+
+        await vm.CleanupWorktreesCommand.ExecuteAsync(null);
+
+        Assert.Contains(worker.ExceptionMessage, vm.StatusMessage);
+        Assert.False(vm.IsBusy);
+    }
+
+    [Fact]
+    public async Task ConfirmResetAll_WhenWorkerThrows_ShowsExceptionMessage()
+    {
+        var worker = new ThrowingWorker();
+        var vm = new WorktreesSettingsTabViewModel(worker);
+
+        await vm.ConfirmResetAllCommand.ExecuteAsync(null);
+
+        Assert.Contains(worker.ExceptionMessage, vm.StatusMessage);
+        Assert.False(vm.IsBusy);
+        Assert.False(vm.ShowResetConfirm);
+    }
+}