添加代理节点功能，包括节点注册、心跳检测和配置获取，完善相关API路由和服务逻辑

atsf_server/common/constants.go

@@ -45,6 +45,8 @@ var WeChatAccountQRCodeImageURL = ""
 
 var TurnstileSiteKey = ""
 var TurnstileSecretKey = ""
+var AgentToken = ""
+var NodeOfflineThreshold = 2 * time.Minute
 
 const (
 	RoleGuestUser  = 0

atsf_server/common/init.go

@@ -50,6 +50,9 @@ func init() {
 	if os.Getenv("UPLOAD_PATH") != "" {
 		UploadPath = os.Getenv("UPLOAD_PATH")
 	}
+	if os.Getenv("AGENT_TOKEN") != "" {
+		AgentToken = os.Getenv("AGENT_TOKEN")
+	}
 	if *LogDir != "" {
 		var err error
 		*LogDir, err = filepath.Abs(*LogDir)