iter(g91): 表单字段补辅助说明 hint

apps/demo/main.ts

@@ -421,7 +421,7 @@ const content = h(
       { submitText: '注册', onSubmit: () => formResult(`提交成功：${username()} / ${email()} / ${city()}`) },
       [
         formItem({ label: '用户名', required: true, value: username, rules: [{ min: 2, max: 12, message: '用户名需 2-12 个字符' }] }, textField({ placeholder: '2-12 个字符', value: username })),
-        formItem({ label: '邮箱', required: true, value: email, rules: [{ pattern: /^[\w.-]+@[\w-]+\.[\w.]+$/, message: '邮箱格式不正确' }] }, textField({ placeholder: 'you@example.com', value: email })),
+        formItem({ label: '邮箱', required: true, value: email, hint: '用于登录与找回密码，不会公开', rules: [{ pattern: /^[\w.-]+@[\w-]+\.[\w.]+$/, message: '邮箱格式不正确' }] }, textField({ placeholder: 'you@example.com', value: email })),
         formItem({ label: '城市', required: true, value: city }, select({ options: cities.map((c) => ({ value: c, label: c })), value: city, placeholder: '请选择城市…' })),
         formItem(
           { label: '邀请码', required: true, value: inviteCode, rules: [{ validator: async (v) => { await new Promise((r) => setTimeout(r, 400)); return v === 'USED' ? '该邀请码已被使用' : true; }, message: '校验未通过' }] },