Adds getLyricsBySongId (versions 1 and 2 of the songLyrics extension,
gated by the enhanced param): returns every stored structuredLyrics
entry for a song, including line-level start times for synced lyrics
and, only when a source actually provided word/syllable timing (an
Enhanced LRC sidecar) and enhanced=true was requested, cueLine/cue
data with the precomputed UTF-8 byte offsets. Plain and non-enhanced
synced lyrics never get fabricated cue data.
Removes the now-dead SetSongLyrics writer (superseded by
database.InsertLyrics); SongLyricsPlainText keeps serving the legacy
getLyrics endpoint unchanged.
Adds a scanner integration test proving a sidecar .lrc (with an
Enhanced LRC line) is discovered and indexed during a real scan.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014r98AtcBbevpscWLsfwVvv
