feat: Implement the initial backend HTTP API server with configuration, logging, S2A proxy, mail service management, and team owner database operations.

backend/cmd/main.go

@@ -271,6 +271,8 @@ func handleS2AProxy(w http.ResponseWriter, r *http.Request) {
 		targetURL += "?" + r.URL.RawQuery
 	}
 
+	logger.Info(fmt.Sprintf("S2A Proxy: %s -> %s", r.URL.Path, targetURL), "", "proxy")
+
 	// 创建代理请求
 	proxyReq, err := http.NewRequest(r.Method, targetURL, r.Body)
 	if err != nil {
@@ -278,26 +280,31 @@ func handleS2AProxy(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	// 复制请求头
-	for key, values := range r.Header {
-		for _, value := range values {
-			proxyReq.Header.Add(key, value)
-		}
-	}
+	// 设置认证头 - 尝试多种格式
+	adminKey := config.Global.S2AAdminKey
+	logger.Info(fmt.Sprintf("Using admin key (len=%d, prefix=%s...)", len(adminKey), adminKey[:min(8, len(adminKey))]), "", "proxy")
 
-	// 设置认证头
-	proxyReq.Header.Set("Authorization", "Bearer "+config.Global.S2AAdminKey)
+	proxyReq.Header.Set("Authorization", "Bearer "+adminKey)
+	proxyReq.Header.Set("X-API-Key", adminKey)
+	proxyReq.Header.Set("X-Admin-Key", adminKey) // 可能是这个
 	proxyReq.Header.Set("Content-Type", "application/json")
+	proxyReq.Header.Set("Accept", "application/json")
 
 	// 发送请求
 	client := &http.Client{Timeout: 30 * time.Second}
 	resp, err := client.Do(proxyReq)
 	if err != nil {
+		logger.Error(fmt.Sprintf("S2A 请求失败: %v", err), "", "proxy")
 		api.Error(w, http.StatusBadGateway, fmt.Sprintf("请求 S2A 失败: %v", err))
 		return
 	}
 	defer resp.Body.Close()
 
+	// 记录响应状态
+	if resp.StatusCode != 200 {
+		logger.Warning(fmt.Sprintf("S2A 返回 %d", resp.StatusCode), "", "proxy")
+	}
+
 	// 复制响应头
 	for key, values := range resp.Header {
 		for _, value := range values {