- Update upsert_file() to include all 26 new AudioMeta fields
- Update get_file_by_virtual_path() to read all new columns
- Add get_file_metadata_row() for overlay synthesis
- Add update_metadata() for partial metadata updates
- Add clear_overlay() to reset metadata to NULL
- Handle format_layout BLOB with msgpack serialization
- Handle custom_tags JSON with serde_json
- Add 8 comprehensive unit tests
- All 92 tests pass, LSP diagnostics clean
- Implement all 8 FormatHandler trait methods
- Use lofty 0.24 for ID3v2.4 tag creation/parsing
- Map all 36 AudioMeta fields to ID3v2 frames
- Handle ID3v2 header parsing for audio_start
- Detect ID3v1 tags at EOF for audio_end
- Add 13 comprehensive unit tests
- Fix test-utils AudioMeta construction with ..Default::default()
- All tests pass, LSP diagnostics clean
Alexander