feat(ui): My Day actions, orphan-aware grouping, menu restructure

Pending UI work:
- My Day add/remove context actions on task rows (parent removal cascades to children)
- orphan-aware grouping: a child whose parent isn't in view renders as a top-level row, not an indented draft
- shell menu restructure (Worker / Repositories submenus); 'Finalize plan' action, drop 'Queue subtasks sequentially'
- notes editor refinements
- subtask-row hover tweak (Surface3, no transition)
- bump Avalonia 12.0.0 -> 12.0.4

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

@@ -62,7 +62,7 @@ public class NotesEditorViewModelTests
     }
 
     [Fact]
-    public async Task DeleteBullet_RemovesFromStoreAndList()
+    public async Task CommitBullet_EmptyText_RemovesFromStoreAndList()
     {
         var api = new FakeNotes();
         var vm = new NotesEditorViewModel(api);
@@ -70,9 +70,26 @@ public class NotesEditorViewModelTests
         vm.NewBulletText = "weg damit";
         await vm.AddBulletCommand.ExecuteAsync(null);
 
-        await vm.Bullets[0].DeleteCommand.ExecuteAsync(null);
+        vm.Bullets[0].Text = "   ";
+        await vm.CommitBulletCommand.ExecuteAsync(vm.Bullets[0]);
 
         Assert.Empty(vm.Bullets);
         Assert.Empty(api.Store);
     }
+
+    [Fact]
+    public async Task CommitBullet_NonEmptyText_PersistsEdit()
+    {
+        var api = new FakeNotes();
+        var vm = new NotesEditorViewModel(api);
+        await vm.LoadDayAsync(new DateOnly(2026, 6, 1));
+        vm.NewBulletText = "original";
+        await vm.AddBulletCommand.ExecuteAsync(null);
+
+        vm.Bullets[0].Text = "geändert";
+        await vm.CommitBulletCommand.ExecuteAsync(vm.Bullets[0]);
+
+        Assert.Single(vm.Bullets);
+        Assert.Equal("geändert", api.Store[0].Text);
+    }
 }