fix(ui): connection pill opens worker help only when disconnected

The footer pill fired OpenWorkerConnectionHelpCommand unconditionally, so
clicking it on a connected worker showed the "WORKER NOT REACHABLE" dialog.
Gate the command on !IsConnected (not IsOffline — the retry loop stays in
"connecting" forever while the worker is down, which is exactly when the
dialog's "Start Worker" is needed) and re-evaluate CanExecute on connection
state changes.

src/ClaudeDo.Ui/ViewModels/IslandsShellViewModel.cs

@@ -32,6 +32,13 @@ public sealed partial class IslandsShellViewModel : ViewModelBase, IDisposable
 
     public bool IsOffline => Worker?.IsConnected != true && Worker?.IsReconnecting != true;
 
+    // Gate for the footer pill: the help dialog says "WORKER NOT REACHABLE", so it must never open
+    // on a connected worker. Not `IsOffline` — the retry loop stays in "connecting" forever while
+    // the worker is down, and that's exactly when the dialog's "Start Worker" is needed.
+    public bool CanOpenWorkerConnectionHelp => DecideCanOpenConnectionHelp(Worker?.IsConnected == true);
+
+    internal static bool DecideCanOpenConnectionHelp(bool isConnected) => !isConnected;
+
     private readonly UpdateCheckService _updateCheck = null!;
     private readonly InstallerLocator _installerLocator = null!;
     private readonly WorkerLocator _workerLocator = null!;
@@ -346,6 +353,8 @@ public sealed partial class IslandsShellViewModel : ViewModelBase, IDisposable
             {
                 OnPropertyChanged(nameof(ConnectionText));
                 OnPropertyChanged(nameof(IsOffline));
+                OnPropertyChanged(nameof(CanOpenWorkerConnectionHelp));
+                OpenWorkerConnectionHelpCommand.NotifyCanExecuteChanged();
             }
         };
         Worker.WorkerLogReceivedEvent += OnWorkerLogReceived;
@@ -517,7 +526,7 @@ public sealed partial class IslandsShellViewModel : ViewModelBase, IDisposable
         if (Dialogs is not null) await Dialogs.ShowWorkerConnectionAsync(vm);
     }
 
-    [RelayCommand]
+    [RelayCommand(CanExecute = nameof(CanOpenWorkerConnectionHelp))]
     private Task OpenWorkerConnectionHelp() => OpenWorkerConnectionHelpAsync();
 
     [RelayCommand]

tests/ClaudeDo.Ui.Tests/ConnectionPromptGateTests.cs

@@ -19,4 +19,20 @@ public class ConnectionPromptGateTests
         var vm = new IslandsShellViewModel();
         Assert.False(vm.DecideShowConnectionPrompt(isOffline: false));
     }
+
+    // The footer pill binds OpenWorkerConnectionHelpCommand, and the dialog says "WORKER NOT
+    // REACHABLE" — so it must stay closed while the worker is connected, and stay reachable
+    // while it is not (including the endless "connecting" retry state).
+    [Theory]
+    [InlineData(true, false)]
+    [InlineData(false, true)]
+    public void Connection_help_is_gated_on_connected(bool isConnected, bool canOpen)
+        => Assert.Equal(canOpen, IslandsShellViewModel.DecideCanOpenConnectionHelp(isConnected));
+
+    [Fact]
+    public void Connection_help_command_enabled_without_worker()
+    {
+        var vm = new IslandsShellViewModel();
+        Assert.True(vm.OpenWorkerConnectionHelpCommand.CanExecute(null));
+    }
 }