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.Worker/Runner/WorktreeManager.cs

@@ -5,6 +5,7 @@ using ClaudeDo.Data.Repositories;
 using ClaudeDo.Worker.Config;
 using ClaudeDo.Worker.Git;
 using ClaudeDo.Worker.Hub;
+using ClaudeDo.Worker.Lifecycle;
 using ClaudeDo.Worker.Tickets;
 using Microsoft.EntityFrameworkCore;
 
@@ -24,16 +25,19 @@ public sealed class WorktreeManager
     private readonly WorkerConfig _cfg;
     private readonly ILogger<WorktreeManager> _logger;
     private readonly HubBroadcaster? _broadcaster;
+    private readonly RunningOperationRegistry _operations;
 
     public WorktreeManager(
         GitService git, IDbContextFactory<ClaudeDoDbContext> dbFactory, WorkerConfig cfg,
-        ILogger<WorktreeManager> logger, HubBroadcaster? broadcaster = null)
+        ILogger<WorktreeManager> logger, HubBroadcaster? broadcaster = null,
+        RunningOperationRegistry? operations = null)
     {
         _git = git;
         _dbFactory = dbFactory;
         _cfg = cfg;
         _logger = logger;
         _broadcaster = broadcaster;
+        _operations = operations ?? new RunningOperationRegistry();
     }
 
     private Task BroadcastCreating(string taskId) =>
@@ -115,6 +119,7 @@ public sealed class WorktreeManager
 
         // Create the worktree. If a stale branch from a previous run remains
         // (e.g. after force-remove), delete it and retry once.
+        using var creating = _operations.Begin(OperationKinds.CreatingWorktree, task.Title, task.Id, task.Number, task.ListId);
         await BroadcastCreating(task.Id);
         try
         {