fix: preserve agent/task identification in error events and fix exclude propagation

- Add custom handlers for agent_execution_error and task_failed events to
  extract agent_role/agent_id and task_name/task_id before generic serialization
  strips them (these fields are in TRACE_EXCLUDE_FIELDS)
- Remove exclude propagation in __dict__ handler to match Pydantic fallback behavior

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

lib/crewai/src/crewai/events/listeners/tracing/trace_listener.py

@@ -909,6 +909,23 @@ class TraceCollectionListener(BaseEventListener):
         if event_type == "llm_call_completed":
             return _serialize_for_trace(event)
 
+        # Error events need agent/task identification extracted before generic
+        # serialization strips them (agent/task are in TRACE_EXCLUDE_FIELDS)
+        if event_type == "agent_execution_error":
+            event_data = _serialize_for_trace(event)
+            if event.agent:
+                event_data["agent_role"] = getattr(event.agent, "role", None)
+                event_data["agent_id"] = str(getattr(event.agent, "id", ""))
+            return event_data
+        if event_type == "task_failed":
+            event_data = _serialize_for_trace(event)
+            if event.task:
+                event_data["task_name"] = getattr(event.task, "name", None) or getattr(
+                    event.task, "description", None
+                )
+                event_data["task_id"] = str(getattr(event.task, "id", ""))
+            return event_data
+
         # For all other events, use lightweight serialization
         return _serialize_for_trace(event)
 

lib/crewai/src/crewai/utilities/serialization.py

@@ -109,12 +109,12 @@ def to_serializable(
         return repr(obj)
 
     # Handle regular classes with __dict__ (non-Pydantic)
+    # Note: Don't propagate exclude to recursive calls, matching Pydantic fallback behavior
     if hasattr(obj, "__dict__"):
         try:
             return {
                 _to_serializable_key(k): to_serializable(
                     v,
-                    exclude=exclude,
                     max_depth=max_depth,
                     _current_depth=_current_depth + 1,
                     _ancestors=new_ancestors,