fix: langfuse v4 SDK compatibility and pass user message as trace input

services/ws-gateway/app/main.py

@@ -6,8 +6,15 @@ and routes frames between Electron and downstream services via Redis pub/sub.
 This service has NO business logic — it only routes JSON frames.
 """
 
+import sys
 from contextlib import asynccontextmanager
 import logging
+from pathlib import Path
+
+# Ensure the repo root is on sys.path so "shared" is importable in local dev.
+_repo_root = str(Path(__file__).resolve().parents[3])
+if _repo_root not in sys.path:
+    sys.path.insert(0, _repo_root)
 
 from fastapi import FastAPI
 from shared.config import settings