feat: 优化网站性能、响应式设计和测试覆盖率

- 更新next.config.ts配置以优化图片和静态资源
- 优化字体加载策略，减少首屏阻塞
- 使用Next.js Image组件替换img标签并实现懒加载
- 重构移动端菜单交互，提升触摸体验
- 新增安全测试和可访问性测试用例
- 修复导航栏滚动定位问题
- 更新部署就绪测试脚本
- 添加相关文档说明优化细节

src/app/layout.tsx

@@ -10,15 +10,15 @@ import { ErrorBoundary } from "@/components/ui/error-boundary";
 const geistSans = Geist({
   variable: "--font-geist-sans",
   subsets: ["latin"],
-  display: "swap",
-  preload: true,
+  display: "optional",
+  preload: false,
 });
 
 const geistMono = Geist_Mono({
   variable: "--font-geist-mono",
   subsets: ["latin"],
-  display: "swap",
-  preload: true,
+  display: "optional",
+  preload: false,
 });
 
 const notoSansSC = Noto_Sans_SC({
@@ -33,8 +33,8 @@ const maShanZheng = Ma_Shan_Zheng({
   weight: "400",
   variable: "--font-ma-shan-zheng",
   subsets: ["latin"],
-  display: "swap",
-  preload: true,
+  display: "optional",
+  preload: false,
 });
 
 const longCang = Long_Cang({