feat(docs): add Nextra catch-all MDX page

Made-with: Cursor

apps/docs/app/[[...mdxPath]]/page.tsx

@@ -0,0 +1,31 @@
+import { generateStaticParamsFor, importPage } from "nextra/pages";
+import { useMDXComponents as getMDXComponents } from "../../mdx-components";
+
+export const generateStaticParams = generateStaticParamsFor("mdxPath");
+
+/** Nextra Docs Theme 在运行时会提供 `wrapper`；类型上可能为 optional。 */
+const Wrapper = getMDXComponents().wrapper!;
+
+type PageProps = { params: Promise<{ mdxPath?: string[] }> };
+
+export async function generateMetadata(props: PageProps) {
+  const params = await props.params;
+  const { metadata } = await importPage(params.mdxPath);
+  return metadata;
+}
+
+export default async function Page(props: PageProps) {
+  const params = await props.params;
+  const {
+    default: MDXContent,
+    toc,
+    metadata,
+    sourceCode,
+  } = await importPage(params.mdxPath);
+
+  return (
+    <Wrapper toc={toc} metadata={metadata} sourceCode={sourceCode}>
+      <MDXContent {...props} params={params} />
+    </Wrapper>
+  );
+}