feat: migrate metadata engine from id3 to lofty to support FLAC

[RetricSu]

Description

This PR replaces the id3 crate with the lofty crate to provide multi-format metadata support (including FLAC, OGG, M4A, etc.). The entire tag parsing, persistence, lyrics sync, and track cover functionalities have been re-architected.

Changes:

1. Underlying Crate Swap: Removed id3 in favor of lofty (v0.21.1) in Cargo.toml.
2. Library Import Service: Refactored to leverage lofty::Probe for format-agnostic metadata extraction.
3. Lyrics Abstraction: Rewrote lyrics reading and writing to use generic ItemKey::Lyrics format instead of MP3-specific [USLT] frames.
4. Metadata & Image Editor: Overhauled MetadataEditor with generic TaggedFileExt and Accessor traits and added update_track_cover to enable replacing custom cover art.
5. UI Layer Connection: Plumbed the update_track_cover up through PlaylistTableService, LibraryService, and AppCore to expose the capability to the front-end directly.

Closes metadata scaling requests and expands functionality beyond MP3 files.

[gemini-code-assist]

Code Review

This pull request replaces the id3 crate with lofty for audio metadata management, expanding support to formats like FLAC, WAV, OGG, and M4A. It also adds the ability to update and embed album cover art into audio files. The review feedback highlights a potential risk in using Picture::new_unchecked without prior image data validation and suggests a performance optimization for file extension filtering during the library import process.