优化节点列表拉取可能存在失败的可能

(cherry picked from commit f59e70ed8b9084d29f792280d94f1c49719842a1)

lib/app/network/http_util.dart

@@ -14,6 +14,7 @@ import 'package:kaer_with_panels/app/localization/kr_language_utils.dart';
 import 'package:kaer_with_panels/app/utils/kr_common_util.dart';
 import 'package:kaer_with_panels/app/services/singbox_imp/kr_sing_box_imp.dart';
 import 'package:kaer_with_panels/app/services/kr_site_config_service.dart';
+import 'package:kaer_with_panels/singbox/model/singbox_status.dart';
 
 // import 'package:crypto/crypto.dart';
 // import 'package:encrypt/encrypt.dart';
@@ -79,14 +80,44 @@ class HttpUtil {
       createHttpClient: () {
         KRLogUtil.kr_i('📱 createHttpClient 回调被调用', tag: 'HttpUtil');
         final client = HttpClient();
+
+        // ✅ 优化：智能代理回退逻辑
         client.findProxy = (url) {
-          final proxyConfig = KRSingBoxImp.instance.kr_buildProxyRule();
-          KRLogUtil.kr_i(
-            '🔍 findProxy 被调用, url: $url, proxy: $proxyConfig',
-            tag: 'HttpUtil',
-          );
-          return proxyConfig;
+          try {
+            // 检查 SingBox 是否正在运行
+            final singBoxStatus = KRSingBoxImp.instance.kr_status;
+            final isProxyAvailable = singBoxStatus == SingboxStatus.started();
+
+            if (!isProxyAvailable) {
+              // 代理未运行，直接使用直连
+              KRLogUtil.kr_i(
+                '🔄 代理未运行，使用直连模式: $url',
+                tag: 'HttpUtil',
+              );
+              return 'DIRECT';
+            }
+
+            // 代理正在运行，使用代理配置
+            final proxyConfig = KRSingBoxImp.instance.kr_buildProxyRule();
+            KRLogUtil.kr_i(
+              '✅ 使用代理模式, url: $url, proxy: $proxyConfig',
+              tag: 'HttpUtil',
+            );
+            return proxyConfig;
+          } catch (e) {
+            // 发生异常时回退到直连
+            KRLogUtil.kr_w(
+              '⚠️ 代理配置异常，回退到直连: $e',
+              tag: 'HttpUtil',
+            );
+            return 'DIRECT';
+          }
         };
+
+        // ✅ 优化：设置连接失败时的自动回退
+        client.connectionTimeout = const Duration(seconds: 10);
+        client.badCertificateCallback = (cert, host, port) => true;
+
         return client;
       },
     );