refactor: make model sessions explicit

app/db/models/systemconfig.py

@@ -4,7 +4,6 @@ from sqlalchemy.ext.asyncio import AsyncSession
 from sqlalchemy.orm import Mapped, Session, mapped_column
 
 from app.db.base import Base, get_id_column
-from app.db.decorators import legacy_async_db_query, legacy_db_query
 
 
 class SystemConfig(Base):
@@ -18,15 +17,13 @@ class SystemConfig(Base):
     value: Mapped[Optional[Any]] = mapped_column(JSON)
 
     @classmethod
-    @legacy_db_query
     def get_by_key(cls, db: Session, key: str):
-        """按配置键查询系统配置，并保留旧插件无 Session 调用。"""
+        """在调用方 Session 中按配置键查询系统配置。"""
         return db.execute(select(cls).where(cls.key == key)).scalars().first()
 
     @classmethod
-    @legacy_async_db_query
     async def async_get_by_key(cls, db: AsyncSession, key: str):
-        """异步按配置键查询系统配置，并保留旧插件无 Session 调用。"""
+        """在调用方 AsyncSession 中按配置键查询系统配置。"""
         result = await db.execute(select(cls).where(cls.key == key))
         return result.scalar_one_or_none()