new: useCDN option

lib/data/res/build_data.dart

@@ -2,9 +2,9 @@
 
 class BuildData {
   static const String name = "ServerBox";
-  static const int build = 787;
+  static const int build = 793;
   static const String engine = "3.19.2";
-  static const String buildAt = "2024-03-06 16:28:08";
-  static const int modifications = 3;
+  static const String buildAt = "2024-03-08 15:18:32";
+  static const int modifications = 2;
   static const int script = 40;
 }

lib/data/res/url.dart

@@ -1,5 +1,6 @@
 abstract final class Urls {
   static const resBase = 'https://res.lolli.tech/serverbox';
+  static const cdnBase = 'https://cdn.lolli.tech/serverbox';
   static const myGithub = 'https://github.com/lollipopkit';
   static const appHelp = '$myGithub/flutter_server_box#-help';
   static const appWiki = '$myGithub/flutter_server_box/wiki';

lib/data/service/app.dart

@@ -1,11 +1,14 @@
 import 'package:dio/dio.dart';
+import 'package:toolbox/data/res/store.dart';
 
 import '../model/app/update.dart';
 import '../res/url.dart';
 
 class AppService {
   Future<AppUpdate> getUpdate() async {
-    final resp = await Dio().get('${Urls.resBase}/update.json');
+    final useCDN = Stores.setting.useCdn.fetch() == 1;
+    final resp =
+        await Dio().get('${useCDN ? Urls.cdnBase : Urls.resBase}/update.json');
     return AppUpdate.fromJson(resp.data);
   }
 }

lib/data/store/setting.dart

@@ -250,6 +250,11 @@ class SettingStore extends PersistentStore {
   /// when building traffic view on server tab
   late final ignoreLocalNet = property('ignoreLocalNetIface', true);
 
+  /// Use cdn
+  /// It's recommended to use cdn for non-China users
+  /// 0: unset, 1: use, 2: not use
+  late final useCdn = property('useCdn', 0);
+
   // Never show these settings for users
   //
   // ------BEGIN------