fix: improve maintenance and synchronize live conversations

backend/app/repositories/ai_config.py

@@ -16,7 +16,7 @@ limitations under the License.
 
 from sqlalchemy.orm import Session
 from app.models.ai_config import AIConfig, AIModelType, DEFAULT_AI_SETTINGS
-from app.core.security import encrypt_api_key, decrypt_api_key
+from app.core.security import encrypt_api_key
 from typing import Optional