新批次的夜间模式适配代码

lib/pages/battery_health_page.dart

@@ -5,6 +5,7 @@ import 'package:flutter/services.dart';
 import 'package:device_info_plus/device_info_plus.dart';
 
 // --- 本地导入 ---
+import '../main.dart';
 import '../models/device_matching.dart';
 import '../models/saf_permission_state.dart';
 import '../models/data_abnormal_type.dart';
@@ -742,7 +743,18 @@ class _BatteryHealthPageState extends State<BatteryHealthPage> {
                     );
                     break;
                   case 'dark_mode':
-                    // 夜间模式切换逻辑（需要全局状态管理）
+                    // 循环切换：浅色 → 深色 → 跟随系统 → 浅色
+                    final brightness = Theme.of(context).brightness;
+                    ThemeMode next;
+                    if (brightness == Brightness.light) {
+                      next = ThemeMode.dark;
+                    } else if (brightness == Brightness.dark) {
+                      next = ThemeMode.system;
+                    } else {
+                      next = ThemeMode.light;
+                    }
+                    // 🆕 通过全局 key 调用 MyApp 的 switchTheme 方法
+                    appKey.currentState?.switchTheme(next);
                     break;
                 }
               },