refactor: complete Task 2/3 geo decouple + exceptions centralization; mark as done

backend/app/routers/server.py

@@ -15,7 +15,7 @@ from fastapi import APIRouter, HTTPException, Request, status
 from app.dependencies import AuthDep
 from app.models.server import ServerSettingsResponse, ServerSettingsUpdate
 from app.services import server_service
-from app.services.server_service import ServerOperationError
+from app.exceptions import ServerOperationError
 from app.utils.fail2ban_client import Fail2BanConnectionError
 
 router: APIRouter = APIRouter(prefix="/api/server", tags=["Server"])