oa-auth-layout-wecom-login-ux 优化认证页登录布局

client/src/layouts/AuthLayout.tsx

@@ -1,5 +1,4 @@
 import { Outlet } from "react-router-dom";
-import { AppBrand } from "../components/shell/AppBrand";
 import { Button } from "../components/ui/button";
 import { usePwaUpdatePrompt } from "../hooks/usePwaUpdatePrompt";
 
@@ -7,11 +6,8 @@ export function AuthLayout() {
   const { updateReady, applyUpdate, dismissUpdate } = usePwaUpdatePrompt();
 
   return (
-    <div className="min-h-screen bg-slate-50 px-4 py-8 sm:px-6 lg:px-10">
-      <div className="mx-auto flex min-h-[calc(100vh-4rem)] max-w-md flex-col justify-center">
-        <div className="mb-5">
-          <AppBrand />
-        </div>
+    <div className="min-h-screen bg-[var(--color-bg-canvas)] px-4 py-8 sm:px-6 lg:px-10">
+      <div className="mx-auto flex min-h-[calc(100vh-4rem)] max-w-[448px] flex-col justify-center">
         {updateReady ? (
           <div className="mb-4 rounded-xl border border-primary/20 bg-primary/5 px-4 py-3 text-sm text-slate-700" data-testid="auth-pwa-update-notice">
             <div className="font-medium text-slate-900">系统有新版本</div>