feat: migrate all remaining modules from rainyun-go-sdk

- domain(24), product(8), rbm(10), rca(21), rgs(38), ros(19),
  ssl(5), user(10), workorder(11), public remaining 5
- split nested response structs into reusable named types
- rgs reuses rcs request/response types
- fix source bugs: malformed paths, resp vs &resp, missing bodies
- register all 11 services in sdk.New

apis/rgs/nat.go

@@ -0,0 +1,20 @@
+package rgs
+
+import (
+	"fmt"
+
+	"github.com/XingfenD/rainyun_api_go_sdk/apis/common"
+	"github.com/XingfenD/rainyun_api_go_sdk/apis/rcs"
+	"github.com/XingfenD/rainyun_api_go_sdk/constant"
+)
+
+// 添加游戏云NAT端口映射
+//
+// id: 游戏云 ID
+func (s *RgsService) AddRgsNatPortMapping(id int, req *rcs.AddRcsNatPortMappingRequest) (*common.BasicOperationResponse, error) {
+	path := fmt.Sprintf("/product/rgs/%d/nat", id)
+
+	var resp common.BasicOperationResponse
+	err := s.client.Do(constant.HTTPMethod_POST, path, nil, req, &resp)
+	return &resp, err
+}