Replace the substring signal lists in isLyricsProviderUnavailableError
with typed errors (errLyricsNotFound / errLyricsServiceUnavailable in
the new lyrics_errors.go). Providers now classify failures at the point
of origin: HTTP statuses via lyricsHTTPStatusError (429/5xx cooldown),
netease API codes and paxsenix proxy failures as explicit unavailable,
and every "no lyrics/songs found" path as typed not-found.
Substring matching survives only for error payloads from third-party
proxies (rate limit, missing parameters), whose messages genuinely
arrive as free text.
Two deliberate behavior changes: LyricsPlus 429/5xx responses now cool
the provider down (previously unclassified), and proxy payloads saying
"not found" are treated as not-found instead of disabling the provider.
Resolve API (api.zarz.moe):
- Refactor songlink.go: Spotify URLs use resolve API, non-Spotify uses SongLink API
- Add SongLink fallback when resolve API fails for Spotify (two-layer resilience)
- Remove dead code: page parser, XOR-obfuscated keys, legacy helpers
Multi-artist tag fix (#288):
- Add RewriteSplitArtistTags() in Go to rewrite ARTIST/ALBUMARTIST as split Vorbis comments
- Wire method channel handler in Android (MainActivity.kt) and iOS (AppDelegate.swift)
- Add PlatformBridge.rewriteSplitArtistTags() in Dart
- Call native FLAC rewriter after FFmpeg embed when split_vorbis mode is active
- Extract deezerTrackArtistDisplay() helper to use Contributors in album/playlist tracks
Code cleanup:
- Remove unused imports, dead code, and redundant comments across Go and Dart
- Fix build: remove stale getQobuzDebugKey() reference in deezer_download.go