feat(rcs): migrate all RCS APIs from rainyun-go-sdk

- 35 endpoints across 14 files, response structs split for reuse
- Reuse RcsRecord/Node/Plan/OsInfo/UsageData across list/detail/create
- Fix source bugs: {id} path placeholders, missing / in firewall pos path,
  missing body in ChargeRcsTrafic, resp vs &resp
- Add HTTPMethod_PATCH, common.BasicOperationResponse, VncConnectionInfo

apis/rcs/backup.go

@@ -0,0 +1,58 @@
+package rcs
+
+import (
+	"fmt"
+
+	"github.com/XingfenD/rainyun_api_go_sdk/apis/common"
+	"github.com/XingfenD/rainyun_api_go_sdk/constant"
+)
+
+type CreateRcsBackupRequest struct {
+	Label string `json:"label"` // 备份名称
+}
+
+type RcsSetBackupOptionsRequest struct {
+	AutoBackupHour   int `json:"auto_backup_hour"`   // 自动备份时间的小时
+	AutoBackupMinute int `json:"auto_backup_minute"` // 自动备份时间的分钟
+	KeepLast         int `json:"keep_last"`          // 保留份数(1/3/7)
+}
+
+func (s *RcsService) CreateRcsBackup(id int, label string) (*common.BasicOperationResponse, error) {
+	path := fmt.Sprintf("/product/rcs/%d/backup", id)
+
+	var resp common.BasicOperationResponse
+	err := s.client.Do(constant.HTTPMethod_POST, path, nil, CreateRcsBackupRequest{Label: label}, &resp)
+	return &resp, err
+}
+
+func (s *RcsService) DeleteRcsBackup(id, bid int) (*common.BasicOperationResponse, error) {
+	path := fmt.Sprintf("/product/rcs/%d/backup/%d", id, bid)
+
+	var resp common.BasicOperationResponse
+	err := s.client.Do(constant.HTTPMethod_DELETE, path, nil, nil, &resp)
+	return &resp, err
+}
+
+func (s *RcsService) CancelRcsBackup(id, bid int) (*common.BasicOperationResponse, error) {
+	path := fmt.Sprintf("/product/rcs/%d/backup/%d/cancel", id, bid)
+
+	var resp common.BasicOperationResponse
+	err := s.client.Do(constant.HTTPMethod_POST, path, nil, nil, &resp)
+	return &resp, err
+}
+
+func (s *RcsService) RestoreRcsBackup(id, bid int) (*common.BasicOperationResponse, error) {
+	path := fmt.Sprintf("/product/rcs/%d/backup/%d/restore", id, bid)
+
+	var resp common.BasicOperationResponse
+	err := s.client.Do(constant.HTTPMethod_POST, path, nil, nil, &resp)
+	return &resp, err
+}
+
+func (s *RcsService) EnableRcsAutoBackup(id int, req *RcsSetBackupOptionsRequest) (*common.BasicOperationResponse, error) {
+	path := fmt.Sprintf("/product/rcs/%d/backup/setting", id)
+
+	var resp common.BasicOperationResponse
+	err := s.client.Do(constant.HTTPMethod_PATCH, path, nil, req, &resp)
+	return &resp, err
+}