Introduce AppRemoteConfigService which fetches a platform/version/locale-aware JSON payload from api.zarz.moe/v1/spotiflac-mobile/config and caches it in SharedPreferences. main_shell shows a one-shot announcement dialog (respecting dismissible, CTA, time window and version gates) when no update prompt is pending; dismissed IDs are persisted so each announcement surfaces only once.
Tweaks bundled in: the service health dot loses its blur halo in favour of solid Material 3 tones, and AppInfo gains the remote config endpoint constant. The share listener and SAF migration hook stay synchronous inside the post-frame callback so share-intent URLs never race the network-bound checks.
New unit tests cover the announcement CTA/active-window rules.
zarzet