feat(#402): wire screen-scoped providers to liveEventsProvider

#392's dispatcher only invalidates publicly-importable providers
(myQuarantine + home). Screen-scoped providers (file-private in their
feature folders) get their own ref.listen(liveEventsProvider, ...) so
they go live without needing back-edge dependencies from /shared.

Five screens wired:

- library_screen.dart _LikedTab — invalidates _likedTracksProvider /
  _likedAlbumsProvider / _likedArtistsProvider on any of the six
  track/album/artist like/unlike kinds.

- playlist_detail_screen.dart — invalidates playlistDetailProvider(id)
  on playlist.updated / playlist.tracks_changed matching the visible
  playlist_id. On playlist.deleted matching the visible id, pops back
  so the user isn't left staring at a gone playlist.

- admin_requests_screen.dart — invalidates adminRequestsProvider on
  request.status_changed (covers user create/cancel + admin
  approve/reject + reconciler complete).

- admin_quarantine_screen.dart — invalidates adminQuarantineProvider
  on any quarantine.* event (flag from a user / admin resolve / file
  delete / lidarr delete).

- requests_screen.dart (own requests) — invalidates myRequestsProvider
  on request.status_changed. Server-side events are user-scoped via
  publishRequestStatusChanged's row.UserID, so admin actions on
  someone else's request route to the right stream.

History tab is NOT wired (no server-side play.scrobbled event yet —
documented in #402 body as deferred until that event ships).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

flutter_client/lib/playlists/playlist_detail_screen.dart

@@ -7,6 +7,7 @@ import '../cache/db.dart';
 import '../models/playlist.dart';
 import '../models/track.dart';
 import '../player/player_provider.dart';
+import '../shared/live_events_provider.dart';
 import '../shared/widgets/track_actions/track_actions_button.dart';
 import '../theme/theme_extension.dart';
 import 'playlists_provider.dart';
@@ -24,6 +25,23 @@ class PlaylistDetailScreen extends ConsumerWidget {
   @override
   Widget build(BuildContext context, WidgetRef ref) {
     final fs = Theme.of(context).extension<FabledSwordTheme>()!;
+    // #402 wire-up: invalidate the detail provider on playlist.updated /
+    // .tracks_changed events whose payload matches the visible id. On
+    // .deleted matching this id, navigate back so the user isn't left
+    // staring at a gone-from-server playlist.
+    ref.listen<AsyncValue<LiveEvent>>(liveEventsProvider, (_, next) {
+      final e = next.asData?.value;
+      if (e == null) return;
+      final eventPlaylistId = e.data['playlist_id'] as String?;
+      if (eventPlaylistId != id) return;
+      switch (e.kind) {
+        case 'playlist.updated':
+        case 'playlist.tracks_changed':
+          ref.invalidate(playlistDetailProvider(id));
+        case 'playlist.deleted':
+          if (context.mounted) context.pop();
+      }
+    });
     final detail = ref.watch(playlistDetailProvider(id));
 
     // Resolve the best playlist info available for the AppBar title.