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/Services/WorkerClient.cs

@@ -510,9 +510,6 @@ public partial class WorkerClient : ObservableObject, IAsyncDisposable, IWorkerC
     public async Task<PlanningSessionResumeInfo> ResumePlanningSessionAsync(string taskId, CancellationToken ct = default)
         => await _hub.InvokeAsync<PlanningSessionResumeInfo>("ResumePlanningSessionAsync", taskId, ct);
 
-    public async Task ResumeTaskInTerminalAsync(string taskId, CancellationToken ct = default)
-        => await _hub.InvokeAsync("ResumeTaskInTerminal", taskId, ct);
-
     public async Task SubmitTaskForReviewAsync(string taskId, CancellationToken ct = default)
         => await _hub.InvokeAsync("SubmitTaskForReview", taskId, ct);