Remove the never-called checkAvailability chain end to end (Dart bridge +
provider, Android/iOS MethodChannel handlers, Go exports) and stop restoring
its persistent lookup cache on every cold start; the legacy prefs key is
cleared on next cache reset.
Delete dead Go: romaji.go (test-only), the no-op pre-warm chain
(PreWarmTrackCache/PreWarmCache/…), retired Download stubs, and a batch of
exports with no Dart/Kotlin/Swift/Go caller. Kept GetTrackCacheSize/
ClearTrackIDCache (Settings cache screen), SetAllowedDownloadDirs and
Clear/GetItemProgress (live test seams).
Dedup: single updateFlacVorbis + replaceFlacPictures helper behind the six
FLAC tag writers; merge byte-identical extractCommentFrame/extractLyricsFrame
into extractLangTextFrame.
go build/vet + 237 go tests, flutter analyze + tests green.
marshalJSONString collapses 62 identical marshal-and-return blocks in the
gomobile exports; jsError/jsSuccess collapse 135 goja extension-response
maps; the two MusicBrainz fetchers share one request+retry helper; the
extension-HTTP default User-Agent block and fileExists get single homes.
No exported signature changes.
gofmt -r rewrite of all 506 interface{} occurrences to the any alias
(identical semantics), drop unused spec constants into comments, rename
unused parameters to _, convert three if-else chains to tagged
switches, and use slices.ContainsFunc for the private-IP check. No
behavior change; the whole package is now gofmt-clean.
Pure mechanical move within package gobackend — no signature or behavior
change, so the gomobile binding surface is identical. exports.go (4,141
lines) now holds only availability/dir/duplicate/filename exports; the
rest moved to exports_{musicbrainz,download,reenrich,metadata,lyrics,
deezer,extensions,store,library}.go along existing responsibility
boundaries.
zarzet