Re-implements the parked scrobblers-wip stash intent on the current tree
(the stash no longer applied; it remains untouched in the stash list) with
three corrections: the Last.fm offline queue uses the SHARED per-user
offline_settings.db scrobble_queue (byte-identical SQL to Tauri - queues
flush from either frontend) instead of a private table; the ListenBrainz
cache opens Tauri's per-user path so LB creds and listen_queue are truly
shared (a Tauri LB sign-in pre-seeds Slint); and the queue flush is driven
by the offline engine's online edge (plus initial flush), not login-only.
New frontend-agnostic qbz_app::settings::scrobblers store (master enable,
Last.fm session/username, LB token/username; tests) and the shared
scrobble-queue API on OfflineModeStore. Player wiring hooks the de-duped
track-change edge inside the QConnect remote gate: now-playing fires on
change (skipped offline), the scrobble arms at min(50%, 240s) with a
generation counter cancelling stale timers, all sources scrobble (Tauri
parity incl. the #360 version-enriched title). Offline or call failure
queues; Last.fm flush honors the 50-batch and 14-day cutoff.
Settings gains an Integrations section (Plex-section idiom): Last.fm
browser-auth connect/finish/disconnect, ListenBrainz token field +
validate, per-service enable toggles. Known gap documented: Last.fm creds
cannot be shared with Tauri (webview localStorage); LB creds and both
queues are shared.
cc
vicrodh
952846b6a0