feat: 重构导航和博客系统，支持多级菜单和API数据源

- 重构导航菜单支持多级子菜单结构
- 博客系统改为从API获取数据，移除本地文件存储
- 删除旧的关于页面，准备重构
- 修复博客详情页slug匹配问题
- 默认首页重定向到中文版本

app/[locale]/blog/[slug]/page.tsx

@@ -22,8 +22,9 @@ export async function generateMetadata({
 }: MetadataProps): Promise<Metadata> {
   const { locale, slug } = await params;
   let { posts }: { posts: BlogPost[] } = await getPosts(locale);
-  const post = posts.find((post) => post.slug === "/" + slug);
+  const post = posts.find((post) => post.slug === slug);
 
+  console.log(post, posts);
   if (!post) {
     return constructMetadata({
       title: "404",
@@ -50,7 +51,7 @@ export default async function BlogPage({ params }: { params: Params }) {
   const { locale, slug } = await params;
   let { posts }: { posts: BlogPost[] } = await getPosts(locale);
 
-  const post = posts.find((item) => item.slug === "/" + slug);
+  const post = posts.find((item) => item.slug === slug);
 
   if (!post) {
     return notFound();