fix(ui): auto-reconnect worker connection with retry backoff

Add IndefiniteRetryPolicy for WithAutomaticReconnect, wrap initial
StartAsync in a retry loop so the UI keeps retrying when Worker is
offline at startup, and expose IsReconnecting to StatusBar
("Connecting..." / "Online" / "Offline").

src/ClaudeDo.Ui/ViewModels/StatusBarViewModel.cs

@@ -18,9 +18,12 @@ public partial class StatusBarViewModel : ViewModelBase
 
         worker.PropertyChanged += (_, e) =>
         {
-            if (e.PropertyName == nameof(WorkerClient.IsConnected))
+            if (e.PropertyName == nameof(WorkerClient.IsConnected) ||
+                e.PropertyName == nameof(WorkerClient.IsReconnecting))
             {
-                ConnectionStatus = worker.IsConnected ? "Online" : "Offline";
+                ConnectionStatus = worker.IsConnected ? "Online"
+                    : worker.IsReconnecting ? "Connecting..."
+                    : "Offline";
             }
         };