feat: Implement a pool monitoring dashboard and file upload functionality.

backend/cmd/main.go

@@ -264,9 +264,19 @@ func handleS2AProxy(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	// 提取路径: /api/s2a/proxy/xxx -> /api/v1/admin/xxx
+	// 提取路径: /api/s2a/proxy/xxx -> 目标路径
 	path := strings.TrimPrefix(r.URL.Path, "/api/s2a/proxy")
-	targetURL := config.Global.S2AApiBase + "/api/v1/admin" + path
+
+	// 如果路径不是以 /api/ 开通的，默认补上 /api/v1/admin 开头（兼容 dashboard 统计等）
+	// 如果已经是 /api/ 开头（如 /api/pool/polling），则保持原样
+	var targetPath string
+	if strings.HasPrefix(path, "/api/") {
+		targetPath = path
+	} else {
+		targetPath = "/api/v1/admin" + path
+	}
+
+	targetURL := config.Global.S2AApiBase + targetPath
 	if r.URL.RawQuery != "" {
 		targetURL += "?" + r.URL.RawQuery
 	}