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

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

@@ -20,8 +20,8 @@
     <!-- Indent wrapper: col 0 = 24px child indent track, col 1 = content -->
     <Grid Grid.Row="1" ColumnDefinitions="Auto,*">
 
-      <!-- Indent track (only visible for child tasks) -->
-      <Border Grid.Column="0" Width="24" IsVisible="{Binding IsChild}" VerticalAlignment="Stretch">
+      <!-- Indent track (only while the parent shares this view; orphaned children render flat) -->
+      <Border Grid.Column="0" Width="24" IsVisible="{Binding ShowAsChild}" VerticalAlignment="Stretch">
         <Rectangle Width="1" Fill="{DynamicResource LineBrush}"
                    HorizontalAlignment="Right" Margin="0,4"/>
       </Border>
@@ -56,17 +56,23 @@
             <MenuItem Header="{loc:Tr tasks.ctxResumePlanningSession}"
                       Click="OnResumePlanningSessionClick"
                       IsVisible="{Binding CanResumeOrDiscardPlanning}"/>
+            <MenuItem Header="{loc:Tr tasks.ctxFinalizePlanningSession}"
+                      Click="OnFinalizePlanningSessionClick"
+                      IsVisible="{Binding CanFinalizePlanning}"/>
             <MenuItem Header="{loc:Tr tasks.ctxDiscardPlanningSession}"
                       Click="OnDiscardPlanningSessionClick"
                       IsVisible="{Binding CanResumeOrDiscardPlanning}"/>
-            <MenuItem Header="{loc:Tr tasks.ctxQueueSubtasks}"
-                      Click="OnQueuePlanningSubtasksClick"
-                      IsVisible="{Binding CanQueuePlan}"/>
             <Separator/>
             <MenuItem Header="{loc:Tr tasks.ctxScheduleFor}" Click="OnScheduleForClick"/>
             <MenuItem Header="{loc:Tr tasks.ctxClearSchedule}"
                       IsVisible="{Binding HasSchedule}"
                       Click="OnClearScheduleClick"/>
+            <MenuItem Header="{loc:Tr tasks.ctxAddToMyDay}"
+                      IsVisible="{Binding CanAddToMyDay}"
+                      Click="OnAddToMyDayClick"/>
+            <MenuItem Header="{loc:Tr tasks.ctxRemoveFromMyDay}"
+                      IsVisible="{Binding IsMyDay}"
+                      Click="OnRemoveFromMyDayClick"/>
           </ContextMenu>
         </Border.ContextMenu>
         <Grid ColumnDefinitions="0,18,32,*,Auto,Auto,32" Margin="6,8,10,8">