feat(ui): add queueing and scheduling from task row context menu

- Right-click on a task row exposes Send to queue / Remove from queue
  and Schedule for... / Clear schedule actions.
- New virtual:queued list in the sidebar with live count.
- Sidebar counts are now computed (open per list, running, queued,
  review) and refreshed on task- and worker-side events.
- Sending a task to the queue wakes the worker so it starts immediately.

src/ClaudeDo.App/Program.cs

@@ -88,7 +88,9 @@ sealed class Program
                 sp,
                 sp.GetRequiredService<WorkerClient>()));
         sc.AddSingleton<TasksIslandViewModel>(sp =>
-            new TasksIslandViewModel(sp.GetRequiredService<IDbContextFactory<ClaudeDoDbContext>>()));
+            new TasksIslandViewModel(
+                sp.GetRequiredService<IDbContextFactory<ClaudeDoDbContext>>(),
+                sp.GetRequiredService<WorkerClient>()));
         sc.AddSingleton<DetailsIslandViewModel>(sp =>
             new DetailsIslandViewModel(
                 sp.GetRequiredService<IDbContextFactory<ClaudeDoDbContext>>(),