feat: 新增全局确认弹窗、多页面UI优化与网络日志开关

1.  新增全局二次确认弹窗组件confirm_box，支持自定义参数并对标小程序实现
2.  优化班级板块多处UI：
    - 修复point_rank_view中Web端字体溢出问题，使用FittedBox自适应缩放
    - 重构class_update_widgets的PostCard，新增卡片背景控制开关并替换光晕实现
    - 优化class_update_view的在线同学栏与头像组布局，支持动态计算展示数量
    - 调整my_update_detail_page的评论区结构，修复评论高亮与删除浮层定位问题
3.  为dio_client新增网络日志总开关，可按需开启请求响应打印
4.  修复多处代码格式与注释细节问题

lib/core/network/dio_client.dart

@@ -37,31 +37,32 @@ import 'package:talker_dio_logger/talker_dio_logger.dart';
 ///   5. Android 真机请求网络必须加 INTERNET 权限（本工程 Manifest 已加）。
 /// ============================================================
 class DioClient {
+  /// 网络日志总开关：true = 控制台打印请求/响应数据，false = 静默
+  static const bool enableNetworkLog = false;
+
   // ---------- 1. 单例：整个 App 只有一个 Dio ----------
   DioClient._()
-      : _dio = Dio(
-          BaseOptions(
-            // 正式环境接口：统一从 ApiConfig 取，换环境只改 api_config.dart
-            baseUrl: ApiConfig.baseUrl,
-            connectTimeout: const Duration(seconds: 10), // 连接超时
-            sendTimeout: const Duration(seconds: 10), // 发送超时
-            receiveTimeout: const Duration(seconds: 10), // 接收超时
-            headers: {
-              'Content-Type': 'application/json; charset=utf-8',
-            },
-          ),
-        ) {
-    _dio.interceptors.add(
-      TalkerDioLogger(
-        talker: talker,
-        settings: const TalkerDioLoggerSettings(
-          printResponseTime: true,
-          hiddenHeaders: <String>{
-            'authorization',
-          },
+    : _dio = Dio(
+        BaseOptions(
+          // 正式环境接口：统一从 ApiConfig 取，换环境只改 api_config.dart
+          baseUrl: ApiConfig.baseUrl,
+          connectTimeout: const Duration(seconds: 10), // 连接超时
+          sendTimeout: const Duration(seconds: 10), // 发送超时
+          receiveTimeout: const Duration(seconds: 10), // 接收超时
+          headers: {'Content-Type': 'application/json; charset=utf-8'},
         ),
-      ),
-    );
+      ) {
+    if (enableNetworkLog) {
+      _dio.interceptors.add(
+        TalkerDioLogger(
+          talker: talker,
+          settings: const TalkerDioLoggerSettings(
+            printResponseTime: true,
+            hiddenHeaders: <String>{'authorization'},
+          ),
+        ),
+      );
+    }
     _dio.interceptors.add(_buildInterceptors());
   }
 
@@ -89,21 +90,26 @@ class DioClient {
       onRequest: (options, handler) {
         // OSS 直传会带自己的 authorization 头（OSS4-HMAC-SHA256 签名），
         // 任何形式存在 authorization 都不再加 Bearer，否则会覆盖 OSS 签名
-        final hasAuth = options.headers['Authorization'] != null ||
+        final hasAuth =
+            options.headers['Authorization'] != null ||
             options.headers['authorization'] != null;
         if (accessToken != null && !hasAuth) {
           options.headers['Authorization'] = 'Bearer $accessToken';
         }
-        debugPrint('▶ 【请求】${options.method} ${options.uri}');
+        if (enableNetworkLog) {
+          debugPrint('▶ 【请求】${options.method} ${options.uri}');
+        }
         handler.next(options); // 放行
       },
 
       // ② 收到响应后：打印日志
       onResponse: (response, handler) {
-        debugPrint(
-          '◀ 【响应】${response.statusCode} '
-          '${response.requestOptions.method} ${response.requestOptions.uri}',
-        );
+        if (enableNetworkLog) {
+          debugPrint(
+            '◀ 【响应】${response.statusCode} '
+            '${response.requestOptions.method} ${response.requestOptions.uri}',
+          );
+        }
         handler.next(response); // 放行
       },
 
@@ -143,10 +149,8 @@ class DioClient {
     final message = switch (e.type) {
       DioExceptionType.connectionTimeout ||
       DioExceptionType.sendTimeout ||
-      DioExceptionType.receiveTimeout =>
-        '网络连接超时，请稍后重试',
-      DioExceptionType.badResponse =>
-        '服务器开小差了（${e.response?.statusCode}）',
+      DioExceptionType.receiveTimeout => '网络连接超时，请稍后重试',
+      DioExceptionType.badResponse => '服务器开小差了（${e.response?.statusCode}）',
       DioExceptionType.cancel => '请求已取消',
       DioExceptionType.connectionError => '网络异常，请检查网络连接',
       _ => '未知错误（${e.type.name}）',
@@ -262,8 +266,7 @@ class DioClient {
       DioExceptionType.connectionError ||
       DioExceptionType.connectionTimeout ||
       DioExceptionType.sendTimeout ||
-      DioExceptionType.receiveTimeout =>
-        true,
+      DioExceptionType.receiveTimeout => true,
       _ => false,
     };
   }