fix(kr_home_controller): 将超时时间从Duration改为毫秒数值

将KRLatencyTester.testMultipleNodes方法的timeout参数从Duration类型改为直接使用毫秒数值，保持与接口定义一致

lib/app/modules/kr_home/controllers/kr_home_controller.dart

@@ -1932,7 +1932,7 @@ class KRHomeController extends GetxController with WidgetsBindingObserver {
       final results = await KRLatencyTester.testMultipleNodes(
         nodes: nodeAddresses,
         concurrency: 10,  // 每批10个并发
-        timeout: const Duration(seconds: 5),
+        timeout: 5000,    // 超时时间5秒（毫秒）
       );
 
       // 更新节点延迟