Move config validation to top-level

main.py

@@ -310,8 +310,6 @@ class AppContext:
 @asynccontextmanager
 async def lifespan(_server: FastMCP) -> AsyncIterator[AppContext]:
     """Create and configure the vector-search client for the server lifetime."""
-    cfg = Settings.model_validate({})
-
     vs = GoogleCloudVectorSearch(
         project_id=cfg.project_id,
         location=cfg.location,
@@ -349,6 +347,7 @@ def _parse_args() -> argparse.Namespace:
 
 
 _args = _parse_args()
+cfg = Settings.model_validate({})
 
 mcp = FastMCP(
     "knowledge-search",