统一维护与错误页面并修复移动端顶部文案

新增品牌维护页和404页面并补齐网关路由
将临时维护公告迁到release外运行态覆盖并增加构建门禁
同步Nginx、Pingora、部署脚本与生产运维文档
隐藏移动端顶部SEO介绍并保留桌面端与H1语义
增加维护页、404页和移动端回归测试

src/components/rpg-entry/RpgEntryHomeView.recharge.test.tsx

@@ -4133,6 +4133,9 @@ test('desktop home exposes one product h1 and section h2 headings', () => {
 
   expect(screen.getAllByRole('heading', { level: 1 })).toHaveLength(1);
   expect(productHeading.closest('button')).toBeNull();
+  expect(productHeading.closest('header')?.classList.contains('sr-only')).toBe(
+    false,
+  );
   expect(
     screen.getByRole('heading', { level: 2, name: '今日游戏' }),
   ).toBeTruthy();
@@ -4142,7 +4145,7 @@ test('desktop home exposes one product h1 and section h2 headings', () => {
   ).toBeTruthy();
 });
 
-test('mobile shell exposes one product h1 outside interactive content', () => {
+test('mobile shell keeps the product h1 visually hidden outside interactive content', () => {
   renderLoggedOutHomeView(vi.fn(), {}, 'profile');
 
   const productHeading = screen.getByRole('heading', {
@@ -4152,6 +4155,9 @@ test('mobile shell exposes one product h1 outside interactive content', () => {
 
   expect(screen.getAllByRole('heading', { level: 1 })).toHaveLength(1);
   expect(productHeading.closest('button')).toBeNull();
+  expect(productHeading.closest('header')?.classList.contains('sr-only')).toBe(
+    true,
+  );
 });
 
 test('logged in create tab shows real wallet balance beside the brand', () => {

src/components/rpg-entry/RpgEntryHomeView.tsx

@@ -1006,9 +1006,15 @@ function SectionHeader({ title, detail }: { title: string; detail: string }) {
   );
 }
 
-function HomeSeoIntro() {
+function HomeSeoIntro({
+  visuallyHidden = false,
+}: {
+  visuallyHidden?: boolean;
+}) {
   return (
-    <header className="mb-2 min-w-0 shrink-0 px-1">
+    <header
+      className={visuallyHidden ? 'sr-only' : 'mb-2 min-w-0 shrink-0 px-1'}
+    >
       <h1 className="text-sm font-semibold leading-5 text-[var(--platform-text-strong)]">
         游戏美术AI工作台，让个人创作者更快做出角色、场景与宣发素材
       </h1>
@@ -5029,7 +5035,7 @@ export function RpgEntryHomeView({
             </div>
           ) : null}
 
-          <HomeSeoIntro />
+          <HomeSeoIntro visuallyHidden />
 
           <div className="platform-tab-panel-stack min-w-0 flex-1">
             {tabPanels}