🐛 fix LLM MDX endpoint for locale-prefixed pages

Move llms.mdx route from /llms.mdx/docs/[[...slug]] to
/llms.mdx/[lang]/docs/[[...slug]] and pass lang to source.getPage.
Add locale-aware rewrite rule (/:lang/docs/:path*.mdx) and keep the
bare /docs/ rewrite defaulting to en.

https://claude.ai/code/session_01UwMuBPaeouJ16zJTVa8UJm

Author: claude

docs/app/llms.mdx/[lang]/docs/[[...slug]]/route.ts

@@ -0,0 +1,23 @@
+import { getLLMText, source } from "@/lib/source";
+import { notFound } from "next/navigation";
+
+export const revalidate = false;
+
+export async function GET(
+  _req: Request,
+  { params }: { params: Promise<{ lang: string; slug?: string[] }> },
+) {
+  const { lang, slug } = await params;
+  const page = source.getPage(slug, lang);
+  if (!page) notFound();
+
+  return new Response(await getLLMText(page), {
+    headers: {
+      "Content-Type": "text/markdown",
+    },
+  });
+}
+
+export function generateStaticParams() {
+  return source.generateParams();
+}

docs/app/llms.mdx/docs/[[...slug]]/route.ts

@@ -7,9 +7,13 @@ const config = {
   reactStrictMode: true,
   async rewrites() {
     return [
+      {
+        source: '/:lang/docs/:path*.mdx',
+        destination: '/llms.mdx/:lang/docs/:path*',
+      },
       {
         source: '/docs/:path*.mdx',
-        destination: '/llms.mdx/docs/:path*',
+        destination: '/llms.mdx/en/docs/:path*',
       },
     ];
   },