refactor(media): unify media identity and chain responsibilities

app/chain/lrclib.py

@@ -0,0 +1,29 @@
+from typing import Optional, Union
+
+from app.chain import ChainBase
+from app.core.context import MusicInfo, MusicLyrics
+from app.core.meta import MetaMusic
+
+
+class LrclibChain(ChainBase):
+    """LRCLIB 音乐歌词来源链。"""
+
+    def get_music_lyrics(
+            self,
+            music: Union[MetaMusic, MusicInfo],
+    ) -> Optional[MusicLyrics]:
+        """按单曲元数据获取标准化歌词。"""
+        result = self.run_module("music_lyrics", music=music)
+        if isinstance(result, MusicLyrics):
+            return result
+        return MusicLyrics.from_dict(result) if isinstance(result, dict) else None
+
+    async def async_get_music_lyrics(
+            self,
+            music: Union[MetaMusic, MusicInfo],
+    ) -> Optional[MusicLyrics]:
+        """异步按单曲元数据获取标准化歌词。"""
+        result = await self.async_run_module("music_lyrics", music=music)
+        if isinstance(result, MusicLyrics):
+            return result
+        return MusicLyrics.from_dict(result) if isinstance(result, dict) else None