feat(mission-control): show running Worker operations in a Running now section

Registry of active verify/merge/rebase/worktree-creation operations in the Worker,
GetActiveOperations snapshot + OperationStarted/OperationEnded hub events, and a
Running now section in Mission Control with ticking elapsed time.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

src/ClaudeDo.Ui/Services/Interfaces/IWorkerClient.cs

@@ -59,6 +59,11 @@ public interface IWorkerClient : INotifyPropertyChanged
     /// total.</summary>
     event Action<string, string, int, int>? OperationProgressEvent;
 
+    /// <summary>A Worker operation (verify, merge, rebase, worktree creation) began.</summary>
+    event Action<RunningOperationDto>? OperationStartedEvent;
+    /// <summary>The operation with this id finished, failed or threw.</summary>
+    event Action<string>? OperationEndedEvent;
+
     event Action<string, string>? PlanningMergeStartedEvent;
     event Action<string, string>? PlanningSubtaskMergedEvent;
     /// <summary>(planningTaskId, subtaskId, conflictedFiles, externallyDriven). externallyDriven
@@ -208,6 +213,9 @@ public interface IWorkerClient : INotifyPropertyChanged
     Task<string> GetLastPrepLogAsync();
     Task<IReadOnlyList<WorkerLogEntry>> GetRecentLogsAsync();
 
+    /// <summary>Operations running on the Worker right now — the state to start from before applying started/ended events.</summary>
+    Task<IReadOnlyList<RunningOperationDto>> GetActiveOperationsAsync();
+
     Task<List<PrimeScheduleDto>> GetPrimeSchedulesAsync();
     Task<PrimeScheduleDto?> UpsertPrimeScheduleAsync(PrimeScheduleDto dto);
     Task DeletePrimeScheduleAsync(Guid id);