fix(mma): Add explicit reload logic when _cb_load_track fails in _cb_start_track

The test clicks btn_mma_start_track twice with different track_ids.
When _cb_load_track fails for track_a, self.active_track remains None or wrong.
Then track_b loads but we can't distinguish if a later call is for track_a retry
or track_b (which already has an engine). This adds an explicit reload path
when loaded track doesn't match requested track.

src/app_controller.py

@@ -2913,7 +2913,7 @@ class AppController:
    # Ensure it's loaded as active
    if not self.active_track or self.active_track.id != track_id:
     self._cb_load_track(track_id)
-   if self.active_track:
+   if self.active_track and self.active_track.id == track_id:
    # Use the active track object directly to start execution
     print(f"[DEBUG] _cb_start_track: track_id={self.active_track.id}, desc={self.active_track.description}")
     self._set_mma_status("running")
@@ -2923,6 +2923,18 @@ class AppController:
     full_md, _, _ = aggregate.run(flat)
     threading.Thread(target=engine.run, kwargs={"md_content": full_md}, daemon=True).start()
     self._set_status(f"Track '{self.active_track.description}' started.")
+   elif self.active_track and self.active_track.id != track_id:
+   # load_track failed but active_track is still wrong - reload explicitly
+    print(f"[DEBUG] _cb_start_track: load failed, trying reload track_id={track_id}")
+    self._cb_load_track(track_id)
+    if self.active_track and self.active_track.id == track_id:
+     self._set_mma_status("running")
+     engine = multi_agent_conductor.ConductorEngine(self.active_track, self.event_queue, auto_queue=not self.mma_step_mode)
+     self.engines[self.active_track.id] = engine
+     flat = project_manager.flat_config(self.project, self.active_discussion, track_id=self.active_track.id)
+     full_md, _, _ = aggregate.run(flat)
+     threading.Thread(target=engine.run, kwargs={"md_content": full_md}, daemon=True).start()
+     self._set_status(f"Track '{self.active_track.description}' started.")
    return
   idx = 0
   if isinstance(user_data, int):