fix(claude-do): merge Task-Delete mit offener ConPTY-Session blocken + Ghost-Selec

ClaudeDo-Task: df60c0ca-40e5-4284-b887-1cb45244947c

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

@@ -1002,7 +1002,10 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
     private void OnBoundTaskPropertyChanged(object? sender, System.ComponentModel.PropertyChangedEventArgs e)
     {
         if (e.PropertyName == nameof(TaskRowViewModel.HasInteractiveSession))
+        {
             ResetAndRetryCommand.NotifyCanExecuteChanged();
+            DeleteTaskCommand.NotifyCanExecuteChanged();
+        }
     }
 
     [RelayCommand]
@@ -1099,7 +1102,7 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
         CloseDetail?.Invoke();
     }
 
-    private bool CanDeleteTask() => Task != null && _worker.IsConnected;
+    private bool CanDeleteTask() => Task != null && _worker.IsConnected && !Task.HasInteractiveSession;
 
     [RelayCommand]
     private async System.Threading.Tasks.Task CommitSubtaskEditAsync(SubtaskRowViewModel? row)

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

@@ -219,6 +219,13 @@ public sealed partial class TaskRowViewModel : ViewModelBase
     }
     public string? PlanningDisabledReason => PlanningGate().Reason;
 
+    // Deleting out from under a live ConPTY session would orphan the claude process in Mission
+    // Control (it never gets a task-deleted signal) — same rationale as SendToQueueGate.
+    private (bool Can, string? Reason) DeleteGate() =>
+        HasInteractiveSession ? (false, Loc.T("tasks.reasonInteractiveSession")) : (true, null);
+    public bool CanDeleteTask => DeleteGate().Can;
+    public string? DeleteDisabledReason => DeleteGate().Reason;
+
     public bool HasSchedule => ScheduledFor.HasValue;
     // "Add to My Day" — shown on any task not already in My Day; a Done task has no place in
     // today's focus list. The mirror of "Remove from My Day" (gated on IsMyDay).
@@ -402,6 +409,8 @@ public sealed partial class TaskRowViewModel : ViewModelBase
         OnPropertyChanged(nameof(StatusChipTooltip));
         OnPropertyChanged(nameof(CanSendToQueue));
         OnPropertyChanged(nameof(SendToQueueDisabledReason));
+        OnPropertyChanged(nameof(CanDeleteTask));
+        OnPropertyChanged(nameof(DeleteDisabledReason));
     }
 
     partial void OnFailureReasonChanged(string? value)

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

@@ -311,20 +311,28 @@ public sealed partial class TasksIslandViewModel : ViewModelBase, IDisposable
         }
 
         var existing = Items.FirstOrDefault(r => r.Id == taskId);
+        var removed = false;
 
         if (entity is null)
         {
-            if (existing is not null) Items.Remove(existing);
+            if (existing is not null) { Items.Remove(existing); removed = true; }
         }
         else
         {
             var matches = TaskMatchesList(entity, list);
             if (existing is not null && matches)  existing.UpdateFromEntity(entity);
-            else if (existing is not null)        Items.Remove(existing);
+            else if (existing is not null)        { Items.Remove(existing); removed = true; }
             else if (matches)                     { LoadForList(list); return; }
             else                                  return;
         }
 
+        // The row is gone from Items but SelectedTask (and the bound detail pane) would still
+        // point at it — happens when a task is deleted externally (MCP/another session) while
+        // selected here, since that path never runs SelectFrom(null, ...) like the in-UI delete
+        // does.
+        if (removed && SelectedTask == existing)
+            SelectFrom(null, "row-removed");
+
         // Keep the parent's HasQueuedSubtasks flag in sync when a child's status flips.
         if (entity is not null && !string.IsNullOrEmpty(entity.ParentTaskId))
         {
@@ -1191,7 +1199,7 @@ public sealed partial class TasksIslandViewModel : ViewModelBase, IDisposable
     [RelayCommand]
     private async Task DeleteTaskAsync(TaskRowViewModel? row)
     {
-        if (row is null || _worker is null) return;
+        if (row is null || row.HasInteractiveSession || _worker is null) return;
         if (ConfirmAsync is not null)
         {
             var ok = await ConfirmAsync(Loc.T("vm.tasksIsland.deleteTaskConfirm", row.Title));
@@ -1216,6 +1224,7 @@ public sealed partial class TasksIslandViewModel : ViewModelBase, IDisposable
         }
 
         Items.Remove(row);
+        if (SelectedTask == row) SelectFrom(null, "row-removed");
         Regroup();
         UpdateSubtitle();
         TasksChanged?.Invoke(this, EventArgs.Empty);

src/ClaudeDo.Ui/Views/Islands/TaskRowView.axaml.cs

@@ -98,7 +98,7 @@ public partial class TaskRowView : UserControl
         menu.Items.Add(schedule);
 
         menu.Items.Add(new Separator());
-        menu.Items.Add(MakeItem("tasks.ctxDeleteTask", OnDeleteTaskClick));
+        menu.Items.Add(MakeItem("tasks.ctxDeleteTask", OnDeleteTaskClick, reason: row.DeleteDisabledReason));
 
         menu.Open(border);
         e.Handled = true;