refactor(backend): Extract Airtable token refresh to shared utility

- Create app/utils/airtable_token_utils.py for token refresh logic
- Update all connectors to use centralized token refresh function
- Affected connectors: airtable, clickup, confluence, discord, jira, notion, slack, teams
- Improves code reusability and maintainability
- No functional changes, pure refactoring

surfsense_backend/app/connectors/notion_history.py

@@ -10,7 +10,6 @@ from sqlalchemy.future import select
 
 from app.config import config
 from app.db import SearchSourceConnector
-from app.routes.notion_add_connector_route import refresh_notion_token
 from app.schemas.notion_auth_credentials import NotionAuthCredentialsBase
 from app.utils.oauth_security import TokenEncryption
 
@@ -213,6 +212,8 @@ class NotionHistoryConnector:
                     )
 
                 # Refresh token
+                # Lazy import to avoid circular dependency
+                from app.routes.notion_add_connector_route import refresh_notion_token
                 connector = await refresh_notion_token(self._session, connector)
 
                 # Reload credentials after refresh