feat: 邮箱验证码注册+登录协议勾选

- 后端: VerificationCode模型+send-code API+register增加verifyCode校验
- 前端: 注册表单增加验证码输入框+60s倒计时获取按钮
- 前端: 登录表单增加用户协议/隐私政策勾选
- 前端: 登录按钮增加disabled状态(未勾选时不可点击)
- 后端: nodemailer邮件发送工具(可配置SMTP,未配置时返回devCode)

server/package.json

@@ -8,7 +8,12 @@
     "dev": "nodemon src/index.js",
     "test": "jest"
   },
-  "keywords": ["wechat", "miniprogram", "ai", "education"],
+  "keywords": [
+    "wechat",
+    "miniprogram",
+    "ai",
+    "education"
+  ],
   "author": "宇之然团队",
   "license": "MIT",
   "dependencies": {
@@ -27,6 +32,7 @@
     "mongoose": "^8.0.3",
     "morgan": "^1.10.0",
     "multer": "^2.1.1",
+    "nodemailer": "^9.0.3",
     "xml2js": "^0.6.2"
   },
   "devDependencies": {
@@ -37,4 +43,4 @@
   "engines": {
     "node": ">=22.0.0"
   }
-}
+}