Round 3 fixes: cancelled polling, aggregator invalid_count, filter state, scheduler atomicity, HTTP exception handler, tests

app/services/proxy_service.py

@@ -5,7 +5,7 @@ import io
 from datetime import datetime
 from typing import List, Optional, Tuple, AsyncIterator
 
-from app.core.db import get_db, transaction
+from app.core.db import get_db
 from app.repositories.proxy_repo import ProxyRepository
 from app.models.domain import Proxy
 from app.core.log import logger