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_transfer_mark_torrent_completed.py

@@ -2,16 +2,28 @@
 from types import SimpleNamespace
 
 from app.chain.transfer import JobManager, TransferChain
+from app.domain.meta.metabase import MetaBase
 from app.runtime.config import settings
-from app.schemas import FileItem, TransferTask
+from app.schemas import FileItem
+from app.application.transfer import TransferTask
 from app.schemas.types import MediaType
 
 
-class _FakeMeta:
-    """构造最小可用的剧集元数据。"""
+class _FakeMeta(MetaBase):
+    """
+    构造最小可用的剧集元数据。
+
+    继承 MetaBase 而非鸭子类型：TransferTask.meta 已标注为 MetaBase，pydantic 会做
+    isinstance 校验。三个类级属性用来遮蔽 MetaBase 上的同名 property。
+    """
+
+    name = None
+    episode_list = None
+    season_episode = None
 
     def __init__(self, episode: int, season: int = 1):
         """初始化剧集编号相关字段。"""
+        super().__init__(title=f"Test Show S{season:02d}E{episode:02d}")
         self.name = "Test Show"
         self.title = f"Test Show S{season:02d}E{episode:02d}"
         self.year = "2026"