@

docs: reorganize api docs into categorized subdirectories and fill missing docs

- Categorize 77 existing api docs into 16 business-domain subdirectories
  (auth/ad/wallet/coupon/compare/savings/signin/tasks/invite/user/
   device/platform/intent/meituan/other) plus admin/ and internal/
- Split admin/ into 7 sub-resource subdirectories (auth/users/wallet/
  withdraws/feedbacks/admins/ad) with 4 single-file docs at root
- Create 21 new docs covering 28 previously undocumented endpoints:
  ad/watch-report, wallet/transfer-auth (3 endpoints), coupon/session+
  stats+completed-today+prompt (7), invite/me+invitees+bind+landing-track,
  user/onboarding (2), platform/flags+ad-config+app-version,
  intent/step+precoupon/step, analytics/events, order/report,
  report/submit+records, feedback/config+records, trace/finalize
- Add mock request/response JSON examples to all new docs
- Create docs/README.md with full category index for LLM navigation
- Update docs/api/README.md: fix all links, add new endpoint rows,
  replace "no doc" markers with actual links
- Fix back-navigation links (./README.md -> ../README.md or
  ../../README.md) in all moved files
@

docs/api/user/user-profile.md

@@ -0,0 +1,20 @@
+# PATCH /api/v1/user/profile — 修改昵称
+
+> 所属:User 组（前缀 `/api/v1/user`） | 鉴权:Bearer access_token | [← 返回 API 索引](../README.md)
+
+## 入参
+请求体 JSON:
+| 字段 | 类型 | 说明 |
+|---|---|---|
+| `nickname` | string | 昵称,**1-16 字**(前后空格自动 strip,strip 后为空判 400) |
+
+## 出参
+响应 `200`:`UserOut`(返回更新后的完整用户对象,`nickname` 字段已更新)。结构见 [API 索引](./README.md#复用数据结构)。
+
+## 错误码
+- `401` 未带 token / token 无效或过期 / 用户被禁用
+- `422` 字段校验失败(`nickname` 缺失 / 长度超 16 字 / 全空白)
+
+## 说明
+- **服务端持久化**:写入 `user.nickname` 列。这是昵称的唯一数据源——客户端之前的本地缓存退登即丢,改完后下次登录走 [`/auth/me`](./auth-me.md) 与登录响应回传仍生效
+- **strip 行为**:服务端会先去除前后空白再校验长度,所以 `"  bob  "` 等价于 `"bob"`