chore: 初始化TikTok短剧后端项目基础架构

创建了完整的NestJS项目结构，包含配置文件、核心模块、工具类、拦截器、过滤器等基础代码，实现了健康检查、用户认证、管理员RBAC、剧集管理、订单支付、媒体管理等核心功能的基础框架，配置了ESLint、TypeScript、Jest等开发工具链。

README.md

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+# TikTok Short Drama Backend
+
+NestJS backend API for a TikTok Minis short drama app.
+
+## API Contract
+
+All endpoints must follow [docs/api-standard.md](./docs/api-standard.md).
+
+Response shape:
+
+```json
+{
+  "code": 0,
+  "data": {},
+  "message": "success",
+  "timestamp": "2026-06-30T00:00:00.000Z",
+  "requestId": "0f5c2e16-1e44-4d55-93a4-ef7c66d9d1f2",
+  "cost": "3ms"
+}
+```
+
+Paginated list shape:
+
+```json
+{
+  "code": 0,
+  "data": {
+    "list": [],
+    "pagination": {
+      "page": 1,
+      "pageSize": 20,
+      "total": 100
+    }
+  },
+  "message": "success",
+  "timestamp": "2026-06-30T00:00:00.000Z",
+  "requestId": "0f5c2e16-1e44-4d55-93a4-ef7c66d9d1f2",
+  "cost": "3ms"
+}
+```
+
+## Implemented Modules
+
+- `health`: app health check.
+- `logs`: request log lookup by `requestId` and playback error reporting.
+- `dramas`: admin drama and episode configuration, app published content listing.
+- `auth`: TikTok login placeholder that returns a business JWT.
+- `orders`: paid episode orders, TikTok payment webhook, and playback unlock checks.
+- `admin`: admin login, RBAC permissions, roles, and admin user management.
+- `users`: app user listing, detail, and status management for admins.
+
+## Commands
+
+```bash
+pnpm install
+pnpm run start:dev
+pnpm run build
+pnpm run test:e2e
+```
+
+Swagger is available at:
+
+```text
+http://localhost:3000/api/docs
+```
+
+Default admin account for local development:
+
+```text
+username: admin
+password: admin123
+```
+
+## Notes
+
+- The project currently uses in-memory services so the API contract can be developed and tested before MySQL credentials are available.
+- TypeORM entity classes are included for the planned MySQL persistence layer.
+- Replace the TikTok login placeholder with official TikTok Minis login exchange once app credentials are ready.