feat: 音乐识别与刮削统一入口整合

- 音乐识别统一走 recognize_media，移除 MusicChain.recognize/async_recognize 及 /music/search 独立端点
- 音乐刮削收拢到 MediaChain.scrape_music_metadata，消除 MusicChain 对 MediaChain 的嵌套引用
- MetaInfo/MetaInfoPath 增加 force_video 参数，影视附加音轨保留季集归属
- 整理、订阅、搜索、API 层音乐识别入口全部统一

tests/test_transfer_job_manager.py

@@ -861,7 +861,7 @@ class TransferJobManagerTest(unittest.TestCase):
             return_value=storage_chain,
         ), patch(
             "app.chain.transfer.MetaInfoPath",
-            side_effect=lambda path, custom_words=None: FakeMeta(1),
+            side_effect=lambda path, custom_words=None, **kwargs: FakeMeta(1),
         ):
             state, errmsg = TransferChain.do_transfer(
                 chain,
@@ -942,7 +942,7 @@ class TransferJobManagerTest(unittest.TestCase):
             return_value=storage_chain,
         ), patch(
             "app.chain.transfer.MetaInfoPath",
-            side_effect=lambda path, custom_words=None: FakeMeta(1),
+            side_effect=lambda path, custom_words=None, **kwargs: FakeMeta(1),
         ):
             state, errmsg = TransferChain.do_transfer(
                 chain,