refactor(db): 修复异步连接池无界增长，并完成 SQLAlchemy 2.0 迁移与分层归位 (#6320)

tests/test_manual_transfer_history.py

@@ -6,7 +6,7 @@ from app.api.endpoints.transfer import (
 )
 from app.chain.transfer import TransferChain
 from app.runtime.config import settings
-from app.db.transferhistory_oper import TransferHistoryOper
+from app.db.oper.transferhistory import TransferHistoryOper
 from app.application.history import (
     clear_transfer_failures,
     failed_retry_count,