fix(gui): Resolve ImGui stack corruption, JSON serialization errors, and test regressions

src/events.py

@@ -91,7 +91,14 @@ class AsyncEventQueue:
   """
   self._queue.put((event_name, payload))
   if self.websocket_server:
-   self.websocket_server.broadcast("events", {"event": event_name, "payload": payload})
+   # Ensure payload is JSON serializable for websocket broadcast
+   serializable_payload = payload
+   if hasattr(payload, 'to_dict'):
+    serializable_payload = payload.to_dict()
+   elif hasattr(payload, '__dict__'):
+    serializable_payload = vars(payload)
+   
+   self.websocket_server.broadcast("events", {"event": event_name, "payload": serializable_payload})
 
  def get(self) -> Tuple[str, Any]:
   """