按协议判断连接权限，优化权限检查效率

server/fwd/core/conn.go

@@ -92,3 +92,13 @@ func (a FwdAddr) Network() string {
 func (a FwdAddr) String() string {
 	return fmt.Sprintf("%s:%d", a.IP, a.Port)
 }
+
+type AuthContext struct {
+	Timeout float64
+	Payload Payload
+	Meta    map[string]any
+}
+
+type Payload struct {
+	ID uint
+}