提交 Nontonki 短剧原型，准备推送到远程仓库。

Co-authored-by: Cursor <cursoragent@cursor.com>

lib/core/config/locale_controller.dart

@@ -0,0 +1,39 @@
+import 'package:flutter/widgets.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+
+class LocaleController extends ChangeNotifier {
+  LocaleController({SharedPreferencesAsync? preferences})
+    : _preferences = preferences ?? SharedPreferencesAsync();
+
+  final SharedPreferencesAsync _preferences;
+  Locale? _locale;
+  Locale? get locale => _locale;
+
+  Future<void> load() async {
+    try {
+      final code = await _preferences.getString('ui.locale');
+      _locale = switch (code) {
+        'en' => const Locale('en'),
+        'zh' => const Locale('zh'),
+        _ => null,
+      };
+      notifyListeners();
+    } catch (_) {
+      // The system locale remains usable if preferences are unavailable.
+    }
+  }
+
+  Future<void> select(String code) async {
+    _locale = switch (code) {
+      'en' => const Locale('en'),
+      'zh' => const Locale('zh'),
+      _ => null,
+    };
+    notifyListeners();
+    try {
+      await _preferences.setString('ui.locale', code);
+    } catch (_) {
+      // Preference persistence is best effort for this prototype.
+    }
+  }
+}