feat: implement ClickUp OAuth integration and connector support

- Added ClickUp OAuth authentication flow with new environment variables for client ID, client secret, and redirect URI.
- Introduced ClickUpHistoryConnector to manage OAuth-based authentication and token refresh for ClickUp API access.
- Created ClickUp connector routes for OAuth flow, including authorization and callback handling.
- Updated indexing logic to utilize the new ClickUpHistoryConnector, supporting both OAuth and legacy API token methods.
- Enhanced frontend components to reflect the new ClickUp integration and removed legacy API token forms.

surfsense_backend/app/routes/__init__.py

@@ -4,6 +4,7 @@ from .airtable_add_connector_route import (
     router as airtable_add_connector_router,
 )
 from .circleback_webhook_route import router as circleback_webhook_router
+from .clickup_add_connector_route import router as clickup_add_connector_router
 from .confluence_add_connector_route import router as confluence_add_connector_router
 from .discord_add_connector_route import router as discord_add_connector_router
 from .documents_routes import router as documents_router
@@ -52,6 +53,7 @@ router.include_router(slack_add_connector_router)
 router.include_router(discord_add_connector_router)
 router.include_router(jira_add_connector_router)
 router.include_router(confluence_add_connector_router)
+router.include_router(clickup_add_connector_router)
 router.include_router(new_llm_config_router)  # LLM configs with prompt configuration
 router.include_router(logs_router)
 router.include_router(circleback_webhook_router)  # Circleback meeting webhooks