注册支持用户名/手机号/邮箱 + 镜像站部署脚本 + AI 助手 Tool Calling 重构

- Prisma User 模型新增 username 字段（唯一索引）
- 注册先查重复再创建，返回友好中文提示（非 500）
- 登录支持用户名/手机号/邮箱三种方式
- 前端注册表单增加用户名输入框，预校验 2-20 位格式
- 新增 scripts/deploy.sh：一键构建并部署主站+镜像站+重启后端+重载 Nginx
- 镜像站 www.yuzhiran.com.cn Nginx 配置与主站同步
- AI 助手架构升级：用户端/管理后台均采用完整 Tool Calling 架构
- 新增 UserAiAssistantService（18 工具）+ AiAssistantController
- admin 助手新增 search + mark-all-notifications-read 工具
- 修复注册 500 错误：catch Prisma P2002 → BadRequestException
- Baidu Analytics Script 注入 root layout

backend/package.json

@@ -4,7 +4,7 @@
   "description": "宇之然 AI - 后端 API 服务",
   "main": "dist/main.js",
   "scripts": {
-    "build": "nest build",
+    "build": "nest build --tsc",
     "start": "nest start",
     "dev": "nest start --watch",
     "start:prod": "node dist/main",
@@ -38,6 +38,7 @@
     "@nestjs/serve-static": "^5.0.5",
     "@nestjs/swagger": "^11.4.2",
     "@prisma/client": "^5.22.0",
+    "alipay-sdk": "^4.14.0",
     "bcryptjs": "^3.0.3",
     "class-transformer": "^0.5.1",
     "class-validator": "^0.15.1",
@@ -62,6 +63,9 @@
     "@types/node": "^20.19.40",
     "@types/passport-jwt": "^4.0.1",
     "@types/supertest": "^7.2.0",
+    "@typescript-eslint/eslint-plugin": "^8.60.0",
+    "@typescript-eslint/parser": "^8.60.0",
+    "eslint": "^8.57.1",
     "jest": "^30.4.0",
     "supertest": "^7.2.2",
     "ts-jest": "^29.4.9",