Improve settings and playback controls

frontend/lib/providers/settings_provider.dart

@@ -1,6 +1,6 @@
 import 'package:flutter/material.dart';
-import 'package:shared_preferences/shared_preferences.dart';
 import 'package:flutter/foundation.dart';
+import 'package:shared_preferences/shared_preferences.dart';
 
 class SettingsProvider with ChangeNotifier {
   // Use 10.0.2.2 for Android emulator to access host's localhost
@@ -11,9 +11,11 @@ class SettingsProvider with ChangeNotifier {
 
   String _baseUrl = _defaultUrl;
   Color _themeColor = Colors.blue;
+  ThemeMode _themeMode = ThemeMode.system;
 
   String get baseUrl => _baseUrl;
   Color get themeColor => _themeColor;
+  ThemeMode get themeMode => _themeMode;
 
   SettingsProvider() {
     _loadSettings();
@@ -26,6 +28,10 @@ class SettingsProvider with ChangeNotifier {
     if (colorValue != null) {
       _themeColor = Color(colorValue);
     }
+    final savedThemeMode = prefs.getString('themeMode');
+    if (savedThemeMode != null) {
+      _themeMode = _themeModeFromString(savedThemeMode);
+    }
     notifyListeners();
   }
 
@@ -39,7 +45,14 @@ class SettingsProvider with ChangeNotifier {
   void setThemeColor(Color color) async {
     _themeColor = color;
     final prefs = await SharedPreferences.getInstance();
-    await prefs.setInt('themeColor', color.value);
+    await prefs.setInt('themeColor', color.toARGB32());
+    notifyListeners();
+  }
+
+  void setThemeMode(ThemeMode mode) async {
+    _themeMode = mode;
+    final prefs = await SharedPreferences.getInstance();
+    await prefs.setString('themeMode', mode.name);
     notifyListeners();
   }
 
@@ -56,4 +69,15 @@ class SettingsProvider with ChangeNotifier {
     }
     return "$rtmpUrl/$roomId";
   }
+
+  ThemeMode _themeModeFromString(String value) {
+    switch (value) {
+      case 'light':
+        return ThemeMode.light;
+      case 'dark':
+        return ThemeMode.dark;
+      default:
+        return ThemeMode.system;
+    }
+  }
 }