fix: 员工端Header标题显示企业名称而非安职通Logo

- 后端3处登录接口（密码/验证码/auto-login）返回 orgName
- 前端 PortalLayout Header 改为显示 employee.orgName
- 移除 Logo 组件引用

frontend/src/components/layout/PortalLayout.tsx

@@ -5,7 +5,6 @@
 
 import { Link, useLocation, useNavigate } from 'react-router-dom'
 import { DollarSign, FileText, ScrollText, LogOut, CalendarCheck, Home } from 'lucide-react'
-import Logo from '../../components/ui/Logo'
 
 const tabItems = [
   { path: '/portal/home', label: '首页', icon: Home },
@@ -34,9 +33,8 @@ export default function PortalLayout({ children }: { children: React.ReactNode }
       {/* 顶部 Header — 安全区 padding 适配刘海屏 */}
       <header className="sticky top-0 z-30 bg-white border-b border-gray-200 pt-safe">
         <div className="max-w-md mx-auto h-14 flex items-center justify-between px-4">
-          <div className="flex items-center gap-2 min-w-0">
-            <Logo className="w-6 h-6 object-contain flex-shrink-0" />
-            <span className="text-sm font-bold text-gray-900 truncate">安职通</span>
+          <div className="flex items-center min-w-0">
+            <span className="text-sm font-bold text-gray-900 truncate">{employee.orgName || '安职通'}</span>
           </div>
           <div className="flex items-center gap-2 flex-shrink-0">
             {employee.name && (