feat(iptv): introduce settings provider and tab for managing IPTV preferences

lib/features/iptv/providers/settings_provider.dart

@@ -236,6 +236,16 @@ class IptvSettingsNotifier extends StateNotifier<IptvSettings> {
 
   IptvSettingsNotifier(this._ref) : super(const IptvSettings()) {
     _loadSettings();
+    _setupAuthListener();
+  }
+
+  void _setupAuthListener() {
+    _ref.listen<AuthState>(authProvider, (previous, next) {
+      if (previous?.isAuthenticated == false && next.isAuthenticated) {
+        // User just logged in, sync settings from API
+        _fetchFromApi();
+      }
+    });
   }
 
   /// Load settings from SharedPreferences and then API

lib/features/iptv/widgets/settings_tab.dart

@@ -470,10 +470,15 @@ class _SettingsTabState extends ConsumerState<SettingsTab> with SingleTickerProv
                          style: FilledButton.styleFrom(backgroundColor: Colors.orange),
                          onPressed: () {
                            Navigator.pop(context);
-                           // Clear PaintingCache
+                           
+                           // Clear Flutter Image Cache
                            PaintingBinding.instance.imageCache.clear();
                            PaintingBinding.instance.imageCache.clearLiveImages();
                            
+                           // Clear Browser Local Storage (SharedPreferences backend for Web)
+                           html.window.localStorage.clear();
+                           html.window.sessionStorage.clear();
+                           
                            // Reload application
                            html.window.location.reload();
                          },