fix(livetv): show guide without favorites

lib/models/livetv_channel.dart

@@ -31,6 +31,21 @@ String favoriteChannelKey(String source, String id) => '$source\u0000$id';
 String liveTvChannelScopeKey(LiveTvChannel channel) =>
     '${channel.serverId ?? ''}\u0000${channel.liveDvrKey ?? ''}\u0000${channel.key}';
 
+List<LiveTvChannel> filterLiveTvChannelsForFavorites({
+  required List<LiveTvChannel> channels,
+  required bool favoritesOnly,
+  required Iterable<FavoriteChannel> favorites,
+  required String Function(LiveTvChannel channel) sourceForChannel,
+}) {
+  if (!favoritesOnly || favorites.isEmpty) return channels;
+
+  final channelMap = {
+    for (final channel in channels) favoriteChannelKey(sourceForChannel(channel), channel.key): channel,
+  };
+
+  return [for (final favorite in favorites) ?channelMap[favorite.stableKey]];
+}
+
 @JsonSerializable(createToJson: false)
 class LiveTvChannel with MultiServerFields {
   @JsonKey(readValue: _readChannelKey)

lib/screens/livetv/live_tv_screen.dart

@@ -71,15 +71,12 @@ class _LiveTvScreenState extends State<LiveTvScreen>
   final Map<String, String> _favoriteStoreBySource = {};
   final Map<String, FavoriteChannelPersistenceMode> _favoriteModeByStore = {};
 
-  List<LiveTvChannel> get _filteredChannels {
-    if (!_showFavoritesOnly) return _channels;
-    if (_favoriteKeys.isEmpty) return const [];
-    final channelMap = {for (final c in _channels) _favoriteKeyForChannel(c): c};
-    return [
-      for (final fav in _favoriteChannels)
-        if (channelMap.containsKey(fav.stableKey)) channelMap[fav.stableKey]!,
-    ];
-  }
+  List<LiveTvChannel> get _filteredChannels => filterLiveTvChannelsForFavorites(
+    channels: _channels,
+    favoritesOnly: _showFavoritesOnly,
+    favorites: _favoriteChannels,
+    sourceForChannel: _sourceForChannel,
+  );
 
   String _liveServerScopeKey(LiveTvServerInfo serverInfo) => '${serverInfo.serverId}\u0000${serverInfo.dvrKey}';
 

test/models/livetv_channel_test.dart

@@ -16,4 +16,35 @@ void main() {
 
     expect(liveTvChannelScopeKey(a), isNot(liveTvChannelScopeKey(b)));
   });
+
+  test('favorite filtering falls back to all channels when no favorites are loaded', () {
+    final channels = [LiveTvChannel(key: '101'), LiveTvChannel(key: '102')];
+
+    final filtered = filterLiveTvChannelsForFavorites(
+      channels: channels,
+      favoritesOnly: true,
+      favorites: const [],
+      sourceForChannel: (_) => 'server://server-1/provider-a',
+    );
+
+    expect(filtered, same(channels));
+  });
+
+  test('favorite filtering preserves favorite order and source scope', () {
+    final channels = [LiveTvChannel(key: '101'), LiveTvChannel(key: '102'), LiveTvChannel(key: '101')];
+    const sourceA = 'server://server-1/provider-a';
+    const sourceB = 'server://server-2/provider-a';
+
+    final filtered = filterLiveTvChannelsForFavorites(
+      channels: channels,
+      favoritesOnly: true,
+      favorites: [
+        FavoriteChannel(source: sourceB, id: '101'),
+        FavoriteChannel(source: sourceA, id: '102'),
+      ],
+      sourceForChannel: (channel) => identical(channel, channels[2]) ? sourceB : sourceA,
+    );
+
+    expect(filtered, [channels[2], channels[1]]);
+  });
 }