feat(ui): wire avalonia desktop ui to data and worker

App: build a ServiceProvider in Program.cs (AppSettings, SqliteConnectionFactory,
all repositories, GitService, WorkerClient, all view-models), apply schema, then
hand control to Avalonia. App.OnFrameworkInitializationCompleted resolves
MainWindowViewModel from the container.

Ui:
- AppSettings POCO loaded from ~/.todo-app/ui.config.json (db path, hub url).
- WorkerClient wraps HubConnection with auto-reconnect, exposes IsConnected and
  ActiveTasks plus C# events for TaskStarted/Finished/Message/Updated and
  WorktreeUpdated; all inbound events are marshalled to the UI thread.
- ViewModels: MainWindow (lists CRUD via ListEditor dialog), TaskList (load by
  list, add/edit/delete, auto WakeQueue on agent+queued create), TaskItem
  (RunNow gated on connection + status), TaskDetail (description, result, live
  ndjson rolling buffer of 500 lines, worktree branch/diff with merge/keep/
  discard via GitService), StatusBar, ListEditor, TaskEditor.
- Views: 3-pane MainWindow (lists | tasks | detail) with GridSplitters, status
  bar, dialog windows for the editors. Status badges via StatusColorConverter.
- Markdown rendering, folder picker, delete-confirmation, settings dialog and
  scroll-to-bottom on the live log are intentionally TODO -- functional
  scaffold only.

Tests: also debounce the FIFO queue test (poll instead of Task.Delay(200)) so
the assertion isn't racy when the suite runs alongside the slower git tests.
38 tests pass.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/ClaudeDo.Ui/Views/StatusBarView.axaml

@@ -0,0 +1,22 @@
+<UserControl xmlns="https://github.com/avaloniaui"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:vm="using:ClaudeDo.Ui.ViewModels"
+             xmlns:conv="using:ClaudeDo.Ui.Converters"
+             x:Class="ClaudeDo.Ui.Views.StatusBarView"
+             x:DataType="vm:StatusBarViewModel">
+    <Border Background="#222" Padding="6,3">
+        <Grid ColumnDefinitions="Auto,Auto,*,Auto">
+            <StackPanel Grid.Column="0" Orientation="Horizontal" Spacing="6">
+                <Ellipse Width="10" Height="10" VerticalAlignment="Center"
+                         Fill="{Binding ConnectionStatus, Converter={x:Static conv:ConnectionColorConverter.Instance}}"/>
+                <TextBlock Text="{Binding ConnectionStatus}" Foreground="White" VerticalAlignment="Center" FontSize="12"/>
+            </StackPanel>
+
+            <TextBlock Grid.Column="1" Text="{Binding ActiveTasksSummary}" Foreground="LightGray"
+                       VerticalAlignment="Center" Margin="20,0,0,0" FontSize="12"/>
+
+            <TextBlock Grid.Column="3" Text="{Binding StatusMessage}" Foreground="Yellow"
+                       VerticalAlignment="Center" FontSize="12" Margin="0,0,8,0"/>
+        </Grid>
+    </Border>
+</UserControl>