feat(tplus): 新增 T+ 只读同步服务与同步管理

backend/app/models/base.py

@@ -91,6 +91,9 @@ class TPlusSyncMixin:
         String(32), comment="同步批次号（同步模块写入）"
     )
     synced_at: Mapped[datetime | None] = mapped_column(DateTime, comment="最近同步时间")
+    source_updated_at: Mapped[datetime | None] = mapped_column(
+        DateTime, comment="T+ 源数据更新时间（未确认时可为空）"
+    )
 
 
 def mysql_table_args(comment: str, *extra: object) -> tuple[object, ...]: