## Description\nAutomatically remove push tokens from database if Expo returns registration failure errors.\n\n## Files to Edit/Create\n- `backend/src/services/notifications.rs`\n\n## Acceptance Criteria\n- Catch HTTP response errors from Expo push notifications. - Remove invalid tokens from database.\n\n## Guidance / Hints\nDelete target row from user_push_tokens.
Description\nAutomatically remove push tokens from database if Expo returns registration failure errors.\n\n## Files to Edit/Create\n-
backend/src/services/notifications.rs\n\n## Acceptance Criteria\n- Catch HTTP response errors from Expo push notifications.