fix: Log+ignore invalid chat IDs instead of error

Our example notebook currently uses '12345' (which is not a valid
UUID), causing the previous UUID parsing logic to raise HTTP 500.
This change keeps the logic, but logs an error and ignores any
received invalid conversation IDs. Seems not worth fixing the
notebook until we tackle broader deployment question (Terraform for
AgentCore)

Author: athewsey

cx-agent-backend/cx_agent_backend/server.py

@@ -4,6 +4,7 @@
 import time
 import logging
 import sys
+from uuid import UUID
 
 from fastapi import FastAPI, HTTPException, Request
 import structlog
@@ -69,8 +70,14 @@ async def invocations(request: dict, http_request: Request):
         langfuse_tags = input_data.get("langfuse_tags", [])
 
         # Convert conversation_id to UUID
-        from uuid import UUID
-        conversation_id = UUID(conversation_id_str) if conversation_id_str else None
+        try:
+            conversation_id = UUID(conversation_id_str) if conversation_id_str else None
+        except:
+            logger.exception(
+                "Failed to parse provided Conversation ID '%s' to valid UUID - Treating as empty",
+                conversation_id_str
+            )
+            conversation_id = None
 
         if not prompt and not feedback:
             raise HTTPException(status_code=400, detail="Either prompt or feedback must be provided in input.")