- Extract SubsonicRequestParser for HTTP parameter extraction
- Extract SubsonicResponseBuilder for XML/JSON response formatting
- Extract SubsonicModelMapper for search result parsing and merging
- Extract SubsonicProxyService for upstream Subsonic server communication
- Add comprehensive test coverage (45 tests) for all new services
- Reduce SubsonicController from 1174 to 666 lines (-43%)
All tests passing. Build succeeds with 0 errors.
