Enhance agent workflows and tools: unify subscription and download processes, add site querying functionality, and improve error handling in download operations.

app/db/models/site.py

@@ -66,6 +66,12 @@ class Site(Base):
         result = await db.execute(select(cls).where(cls.domain == domain))
         return result.scalar_one_or_none()
 
+    @classmethod
+    @async_db_query
+    async def async_get_by_name(cls, db: AsyncSession, name: str):
+        result = await db.execute(select(cls).where(cls.name == name))
+        return result.scalar_one_or_none()
+
     @classmethod
     @db_query
     def get_actives(cls, db: Session):

app/db/site_oper.py

@@ -85,6 +85,12 @@ class SiteOper(DbOper):
         """
         return await Site.async_get_by_domain(self._db, domain)
 
+    async def async_get_by_name(self, name: str) -> Site:
+        """
+        异步按名称获取站点
+        """
+        return await Site.async_get_by_name(self._db, name)
+
     def get_domains_by_ids(self, ids: List[int]) -> List[str]:
         """
         按ID获取站点域名