feat: Add notifications API routes and integrate with frontend

- Introduced new notifications API routes for marking notifications as read and marking all as read, with automatic syncing via Electric SQL.
- Updated the frontend hook to utilize the new API for marking notifications as read, enhancing the user experience with real-time updates.
- Included necessary response models for API interactions.

surfsense_backend/app/routes/__init__.py

@@ -25,6 +25,7 @@ from .luma_add_connector_route import router as luma_add_connector_router
 from .new_chat_routes import router as new_chat_router
 from .new_llm_config_routes import router as new_llm_config_router
 from .notes_routes import router as notes_router
+from .notifications_routes import router as notifications_router
 from .notion_add_connector_route import router as notion_add_connector_router
 from .podcasts_routes import router as podcasts_router
 from .rbac_routes import router as rbac_router
@@ -61,3 +62,4 @@ router.include_router(new_llm_config_router)  # LLM configs with prompt configur
 router.include_router(logs_router)
 router.include_router(circleback_webhook_router)  # Circleback meeting webhooks
 router.include_router(surfsense_docs_router)  # Surfsense documentation for citations
+router.include_router(notifications_router)  # Notifications with Electric SQL sync