fix: 修复 CDN 刷新静默失败问题

- 添加 CDN 刷新日志输出，便于排查问题
- 添加密钥配置检查，未配置时给出明确提示
- 修复生产环境日志不输出的问题
- CDN 刷新失败不影响上传结果，仅记录警告

src/qiniu-uploader.js

@@ -153,25 +153,51 @@ class QiniuUploader {
   }
 
   // 刷新 CDN
-  async refreshCDN(bucketName, key) {
+  async refreshCDN(bucketName, key, logCallback) {
     const bucketConfig = this.config.buckets[bucketName];
-    if (!bucketConfig) return;
+    if (!bucketConfig) {
+      if (logCallback) logCallback(`[CDN 刷新] 存储桶 "${bucketName}" 配置不存在`);
+      return;
+    }
 
     const { accessKey, secretKey, domain } = bucketConfig;
+    
+    // 检查密钥是否有效
+    if (!accessKey || !secretKey || accessKey === 'YOUR_ACCESS_KEY' || secretKey === 'YOUR_SECRET_KEY') {
+      if (logCallback) logCallback(`[CDN 刷新] 警告：存储桶 "${bucketName}" 的密钥未配置，跳过 CDN 刷新`);
+      return;
+    }
+
     const fileUrl = `${domain}/${key}`;
+    if (logCallback) logCallback(`[CDN 刷新] 请求刷新 URL: ${fileUrl}`);
 
     const body = JSON.stringify({ urls: [fileUrl] });
     const accessToken = this.generateAccessToken(accessKey, secretKey, 'POST', '/v2/tune/refresh', body);
 
-    await this.httpRequest('https://fusion.qiniuapi.com/v2/tune/refresh', {
-      method: 'POST',
-      headers: {
-        'Host': 'fusion.qiniuapi.com',
-        'Content-Type': 'application/json',
-        'Content-Length': body.length,
-        'Authorization': accessToken
+    try {
+      const result = await this.httpRequest('https://fusion.qiniuapi.com/v2/tune/refresh', {
+        method: 'POST',
+        headers: {
+          'Host': 'fusion.qiniuapi.com',
+          'Content-Type': 'application/json',
+          'Content-Length': body.length,
+          'Authorization': accessToken
+        }
+      }, body);
+
+      if (logCallback) logCallback(`[CDN 刷新] 响应状态：${result.status}, 数据：${JSON.stringify(result.data)}`);
+
+      if (result.status !== 200) {
+        throw new Error(`CDN 刷新失败：${JSON.stringify(result.data)}`);
       }
-    }, body);
+
+      if (logCallback) logCallback(`[CDN 刷新] ✅ 刷新成功`);
+
+      return result.data;
+    } catch (error) {
+      if (logCallback) logCallback(`[CDN 刷新] ❌ 错误：${error.message}`);
+      throw error;
+    }
   }
 
   // 生成上传凭证