Closes Scribe #614, #615, server half of #616 surfaced by the 2026-06-04 divergent-provider audit.
- streamURL helper now used everywhere /api/tracks/{id}/stream is built (was inline concat in playlists.go and cast_token.go); add streamURLWithExt for the .ext cast variant.
- audioContentType in media.go is the canonical file_format -> MIME lookup; mimeForFormat in cast_token.go is now a thin wrapper that overrides the unknown-format fallback to audio/mpeg (Sonos rejects octet-stream). Adds mpeg/vorbis/wave aliases. Subsonic's contentTypeForFormat stays frozen per docs.
- coverart.ResolveAlbumPath extracted; api and subsonic both delegate to it.
handleStar's track branch calls playevents.CaptureContextualLikeIfPlaying
when the underlying LikeTrack actually inserted a row. handleUnstar
calls SoftDeleteContextualLikes after every track-id unstar. Same
helpers as the api surface — single source of truth.
mediaHandlers struct gains a logger field threaded through Mount.
submission=false → play_started (replaces in-memory nowPlayingMap).
submission=true (default) → synthetic completed play. The nowPlayingMap
struct + factory + the nowPlaying field on mediaHandlers are deleted;
play_events WHERE ended_at IS NULL is now the source of truth for
'currently playing,' reachable from M3+ work.
api.Mount now takes the shared *playevents.Writer instead of cfg so
the same writer instance feeds both surfaces.
http.ServeContent handles Range/ETag/If-Modified-Since; download forces
attachment disposition. getCoverArt tries albums.cover_art_path, then
falls back to cover.{jpg,jpeg,png}/folder.{jpg,jpeg,png} next to the first
track's file. scrobble submission=false records a track into an in-memory
nowPlaying map keyed by user — M2 will read this and wire real events.
bvandeusen