feat: Introduce core IPTV features, authentication screen, web player, and application theming.

lib/features/iptv/providers/favorites_provider.dart

@@ -0,0 +1,35 @@
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+
+/// Manages the list of favorite channel IDs
+class FavoritesNotifier extends StateNotifier<List<String>> {
+  FavoritesNotifier() : super([]) {
+    _loadFavorites();
+  }
+
+  static const String _key = 'xtremflow_favorites';
+
+  Future<void> _loadFavorites() async {
+    final prefs = await SharedPreferences.getInstance();
+    final favorites = prefs.getStringList(_key) ?? [];
+    state = favorites;
+  }
+
+  Future<void> toggleFavorite(String streamId) async {
+    final prefs = await SharedPreferences.getInstance();
+    if (state.contains(streamId)) {
+      state = state.where((id) => id != streamId).toList();
+    } else {
+      state = [...state, streamId];
+    }
+    await prefs.setStringList(_key, state);
+  }
+
+  bool isFavorite(String streamId) {
+    return state.contains(streamId);
+  }
+}
+
+final favoritesProvider = StateNotifierProvider<FavoritesNotifier, List<String>>((ref) {
+  return FavoritesNotifier();
+});