Start offline on the login screen now enters a full offline session instead
of an empty shell: session scaffolding at the last user, local library DB +
mixtape migrations, offline cache + cached-ids warm, per-user pref stores,
tray and media controls, playback poll loop, settings snapshot - mirroring
Tauri's activate_offline_session checklist. Refuses when no previous session
exists (never opens the empty user-0 profile).
New offline_mode glue binds the shared engine + connectivity actor for the
app lifetime and owns the per-user SubscriptionStateStore: mark_valid on
every successful login, mark_invalid only on an explicit IneligibleUser
verdict, binary 30-day-grace playback predicate, and the Tauri-mirrored
purge-at-activation consumer (previously the Slint build never opened the
store, leaving the grace model inert).
Token-survival fix: a network-failed session restore no longer clears the
saved OAuth token; only an explicit auth rejection does. login_with_token
now preserves the typed ApiError (CoreError::Api) so callers can tell the
two classes apart.
cc
vicrodh
904b5f7b40