feat(mobile): sign-in, tabs, search, collection and background player (M5)

- expo-router app in src/app: connect (server check, recent servers),
  login, mandatory credential / password change, tabs Home / Search /
  Collection / Profile, album and artist pages, full-screen player
- AuthSession per server with the refresh token in expo-secure-store
  (Android Keystore); language from the profile
- player on react-native-track-player: ExoPlayer queue with a
  notification and lock-screen controls via a playback service, 500 MB
  stream cache, quality by network (Wi-Fi high, cellular medium),
  play events with played time, reactions, playback state restore and
  the endless My Wave with feedback
- home: pulsing wave circle driven by BPM / energy in the cover
  palette, activity and mood chips that switch the wave on the fly
- New Architecture is off until react-native-track-player supports it;
  the release build runs codegen only when it is on; query-string is a
  direct dependency because expo-router 5.1 imports it undeclared

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

apps/mobile/src/player/service.ts

@@ -0,0 +1,21 @@
+import TrackPlayer, { Event } from 'react-native-track-player';
+
+import { player } from './controller';
+
+/**
+ * Фоновый сервис: кнопки уведомления, экрана блокировки и гарнитуры. Работает и без UI —
+ * команды уходят прямо в ExoPlayer, а учёт прослушиваний ведёт тот же контроллер.
+ */
+export async function PlaybackService(): Promise<void> {
+  TrackPlayer.addEventListener(Event.RemotePlay, () => void TrackPlayer.play());
+  TrackPlayer.addEventListener(Event.RemotePause, () => void TrackPlayer.pause());
+  TrackPlayer.addEventListener(Event.RemoteStop, () => void TrackPlayer.stop());
+  TrackPlayer.addEventListener(Event.RemoteNext, () => player.next());
+  TrackPlayer.addEventListener(Event.RemotePrevious, () => void player.prev());
+  TrackPlayer.addEventListener(Event.RemoteSeek, ({ position }) => player.seek(position * 1000));
+  // Звонок / голосовой ассистент: приостанавливаем и продолжаем сами (autoHandleInterruptions — для фокуса).
+  TrackPlayer.addEventListener(Event.RemoteDuck, ({ paused, permanent }) => {
+    if (permanent) void TrackPlayer.pause();
+    else if (paused) void TrackPlayer.pause();
+  });
+}