refactor backend module architecture

tests/test_media_source_routing.py

@@ -1,10 +1,10 @@
 from unittest.mock import Mock, patch
 
 from app.chain import ChainBase
-from app.core.context import MediaInfo
-from app.core.meta import MetaBase
+from app.domain.context import MediaInfo
+from app.domain.meta.metabase import MetaBase
 from app.schemas.types import MediaSource, MediaType
-from app.utils.media import (
+from app.domain.media import (
     build_media_key,
     parse_media_source_selection,
     resolve_media_identity,