Type the requester-email extraction cleanly 🟪

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

backend/app/documents/router.py

@@ -49,9 +49,9 @@ def get_requesting_user_email(user: Any = Depends(validate_jwt_token)) -> str:
 
     ADR-0059: the route resolves the user (JWT ``dbId`` -> ``UserModel``) rather
     than only gating the token, and threads the email into the job."""
-    email = getattr(user, "email", None)
+    email: Any = getattr(user, "email", None)
     if email is None and isinstance(user, dict):
-        email = user.get("email")
+        email = cast(dict[str, Any], user).get("email")
     if not email:
         raise HTTPException(
             status_code=400,