feat(worker): add hub methods for list and task agent settings

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/ClaudeDo.Worker/Hub/HubBroadcaster.cs

@@ -23,6 +23,9 @@ public sealed class HubBroadcaster
     public Task TaskUpdated(string taskId) =>
         _hub.Clients.All.SendAsync("TaskUpdated", taskId);
 
+    public Task ListUpdated(string listId) =>
+        _hub.Clients.All.SendAsync("ListUpdated", listId);
+
     public Task RunCreated(string taskId, int runNumber, bool isRetry) =>
         _hub.Clients.All.SendAsync("RunCreated", taskId, runNumber, isRetry);
 }