refactor: reorganize backend module boundaries

app/sdk/services.py

@@ -1,16 +1,16 @@
 """插件可使用的宿主服务发现与运行时门面。"""
 
-from app.extensions.service_registry import ServiceBaseHelper, ServiceConfigHelper
-from app.platform.runtime import SystemHelper
-from app.services.downloader import DownloaderHelper
-from app.services.filter import RuleHelper
-from app.services.mediaserver import (
+from app.runtime.extensions.service_registry import ServiceBaseHelper, ServiceConfigHelper
+from app.runtime.state import SystemHelper
+from app.application.downloader import DownloaderHelper
+from app.application.filter import RuleHelper
+from app.application.mediaserver import (
     MediaServerIdentityHelper,
     MediaServerHelper,
     MusicMediaServerHelper,
 )
-from app.services.storage import StorageHelper
-from app.services.notification import NotificationHelper
+from app.application.storage import StorageHelper
+from app.application.notification import NotificationHelper
 
 
 __all__ = [