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)

client/src/pages.json

@@ -15,7 +15,8 @@
     {"path": "pages/dimension/dimension", "style": {"navigationBarTitleText": "", "navigationStyle": "custom"}},
     {"path": "pages/chat/chat", "style": {"navigationBarTitleText": "AI 问答", "navigationStyle": "custom"}},
     {"path": "pages/trend/trend", "style": {"navigationBarTitleText": "AI 趋势", "navigationStyle": "custom"}},
-    {"path": "pages/profile/profile", "style": {"navigationBarTitleText": "我的", "navigationStyle": "custom"}}
+    {"path": "pages/profile/profile", "style": {"navigationBarTitleText": "我的", "navigationStyle": "custom"}},
+    {"path": "pages/agreement/agreement", "style": {"navigationBarTitleText": "协议", "navigationStyle": "custom"}}
   ],
   "globalStyle": {
     "navigationBarTextStyle": "black",