feat(ui): add Restart worker menu entry under Help

Stops and starts the ClaudeDoWorker Windows service via
ServiceController. SignalR auto-reconnect plus the existing
ConnectionRestoredEvent handle the refresh, so the UI repopulates
counters and the active list once the worker is back up.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/ClaudeDo.Ui/ClaudeDo.Ui.csproj

@@ -11,6 +11,7 @@
     <PackageReference Include="Microsoft.AspNetCore.SignalR.Client" Version="8.0.11" />
     <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="8.0.1" />
     <PackageReference Include="Microsoft.Win32.Registry" Version="5.0.0" />
+    <PackageReference Include="System.ServiceProcess.ServiceController" Version="8.0.0" />
   </ItemGroup>
 
   <ItemGroup>

src/ClaudeDo.Ui/ViewModels/IslandsShellViewModel.cs

@@ -255,6 +255,51 @@ public sealed partial class IslandsShellViewModel : ViewModelBase
         await _updateCheck.CheckNowAsync(CancellationToken.None);
     }
 
+    [ObservableProperty] private string? _restartWorkerStatus;
+
+    [RelayCommand]
+    private async Task RestartWorkerAsync()
+    {
+        if (!OperatingSystem.IsWindows())
+        {
+            await FlashRestartStatusAsync("Service control is Windows-only.");
+            return;
+        }
+
+        RestartWorkerStatus = "Restarting worker…";
+        try
+        {
+            await Task.Run(() =>
+            {
+                using var sc = new System.ServiceProcess.ServiceController("ClaudeDoWorker");
+                if (sc.Status != System.ServiceProcess.ServiceControllerStatus.Stopped)
+                {
+                    sc.Stop();
+                    sc.WaitForStatus(System.ServiceProcess.ServiceControllerStatus.Stopped, TimeSpan.FromSeconds(20));
+                }
+                sc.Start();
+                sc.WaitForStatus(System.ServiceProcess.ServiceControllerStatus.Running, TimeSpan.FromSeconds(20));
+            });
+            await FlashRestartStatusAsync("Worker restarted.");
+        }
+        catch (InvalidOperationException)
+        {
+            // ServiceController throws this when the service is not installed.
+            await FlashRestartStatusAsync("ClaudeDoWorker service is not installed.");
+        }
+        catch (Exception ex)
+        {
+            await FlashRestartStatusAsync($"Restart failed: {ex.Message}");
+        }
+    }
+
+    private async Task FlashRestartStatusAsync(string text)
+    {
+        RestartWorkerStatus = text;
+        await Task.Delay(3000);
+        if (RestartWorkerStatus == text) RestartWorkerStatus = null;
+    }
+
     [RelayCommand]
     private void DismissBanner()
     {

src/ClaudeDo.Ui/Views/MainWindow.axaml

@@ -67,6 +67,8 @@
                       Foreground="{DynamicResource TextDimBrush}">
               <MenuItem Header="Check for updates"
                         Command="{Binding CheckForUpdatesCommand}"/>
+              <MenuItem Header="Restart worker"
+                        Command="{Binding RestartWorkerCommand}"/>
               <MenuItem Header="About…" Command="{Binding OpenAboutCommand}"/>
             </MenuItem>
           </Menu>