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

docs/CHANGELOG.md

@@ -6,6 +6,14 @@ All notable changes to this template should be documented in this file.
 The format loosely follows Keep a Changelog and can be adapted to the team's habits.
 本文档参考了 Keep a Changelog 的思路，也可以根据团队习惯调整。
 
+## [0.1.0] - 2026-08-05
+
+### Added / 新增
+
+- 从 `rainyun-go-sdk` 迁移 RCS 全部 35 个接口（列表/详情/创建/备份/防火墙/监控/NAT/续费/升降级等），响应结构体嵌套已拆分复用（`RcsRecord`、`Node`、`Plan`、`OsInfo`、`UsageData` 等）。
+- 新增 `apis/common` 基础类型：`BasicOperationResponse`、`VncConnectionInfo`。
+- `constant` 新增 `HTTPMethod_PATCH`。
+
 ## [0.0.0] - 2026-08-02
 
 ### Notes / 说明