refactor(ui): remove pick-up-in-terminal, keep ConPTY as the single session entry

Two context-menu entries opened a Claude session for the same task via different
mechanisms (embedded ConPTY vs. an external wt terminal). Drop the external-terminal
path entirely, including its worker hub method, launcher plumbing, and localization
keys, since the embedded ConPTY session already covers every case it did.

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

@@ -82,12 +82,6 @@ public partial class TaskRowView : UserControl
             vm.OpenConPtySessionCommand.Execute(row);
     }
 
-    private async void OnPickUpInTerminalClick(object? sender, RoutedEventArgs e)
-    {
-        if (DataContext is TaskRowViewModel row && FindTasksVm() is { } vm)
-            await vm.PickUpInTerminalCommand.ExecuteAsync(row);
-    }
-
     private async void OnResumePlanningSessionClick(object? sender, RoutedEventArgs e)
     {
         if (DataContext is TaskRowViewModel row && FindTasksVm() is { } vm)