feat(ui): pinned Notes row in My Day opens the notes editor

Add ShowNotesRow/OpenNotesCommand to TasksIslandViewModel; wire NotesRequested
event to Details.ShowNotes() in the shell; show a Notes button above the task
list when the My Day smart list is active.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

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

@@ -25,8 +25,16 @@ public sealed partial class TasksIslandViewModel : ViewModelBase
     public event EventHandler? SelectionChanged;
     public event EventHandler? FocusAddTaskRequested;
     public event EventHandler? TasksChanged;
+    public event Action? NotesRequested;
     public void RequestFocusAddTask() => FocusAddTaskRequested?.Invoke(this, EventArgs.Empty);
 
+    [RelayCommand]
+    private void OpenNotes()
+    {
+        SelectedTask = null;
+        NotesRequested?.Invoke();
+    }
+
     public ObservableCollection<TaskRowViewModel> Items { get; } = new();
     public ObservableCollection<TaskRowViewModel> OverdueItems { get; } = new();
     public ObservableCollection<TaskRowViewModel> OpenItems { get; } = new();
@@ -45,6 +53,7 @@ public sealed partial class TasksIslandViewModel : ViewModelBase
     [ObservableProperty] private bool _hasCompleted;
     [ObservableProperty] private bool _showOpenLabel;
     [ObservableProperty] private string _completedHeader = "COMPLETED";
+    [ObservableProperty] private bool _showNotesRow;
 
     public Func<UnfinishedPlanningModalViewModel, Task>? ShowUnfinishedPlanningModal { get; set; }
 
@@ -176,10 +185,12 @@ public sealed partial class TasksIslandViewModel : ViewModelBase
         HasOpen       = false;
         HasCompleted  = false;
         ShowOpenLabel = false;
+        ShowNotesRow  = false;
         if (list is null) return;
 
         HeaderTitle = list.Name;
         HeaderEyebrow = DateTime.Now.ToString("dddd · MMM dd", CultureInfo.InvariantCulture).ToUpperInvariant();
+        ShowNotesRow = list.Id == "smart:my-day";
 
         _ = LoadForListAsync(list, ct);
     }