feat(docs-site): add agent-readable docs routes

docs-site/middleware.ts

@@ -0,0 +1,51 @@
+import { NextResponse, type NextRequest } from "next/server";
+
+const markdownMimeTypes = new Set([
+  "text/markdown",
+  "text/x-markdown",
+  "application/markdown",
+]);
+
+export function middleware(request: NextRequest) {
+  if (!isMarkdownPreferred(request.headers.get("accept"))) {
+    return NextResponse.next();
+  }
+
+  const { pathname } = request.nextUrl;
+  if (!pathname.startsWith("/docs/") || pathname.endsWith(".md")) {
+    return NextResponse.next();
+  }
+
+  const rewriteUrl = request.nextUrl.clone();
+  rewriteUrl.pathname = `/llms.mdx${pathname}`;
+
+  return NextResponse.rewrite(rewriteUrl);
+}
+
+export const config = {
+  matcher: ["/docs/:path*"],
+};
+
+function isMarkdownPreferred(acceptHeader: string | null) {
+  if (!acceptHeader) return false;
+
+  const accepted = acceptHeader
+    .split(",")
+    .map((entry, index) => {
+      const [type = "", ...parameters] = entry.trim().split(";");
+      const quality = parameters
+        .map((parameter) => parameter.trim())
+        .find((parameter) => parameter.startsWith("q="));
+
+      return {
+        type: type.toLowerCase(),
+        quality: quality ? Number.parseFloat(quality.slice(2)) : 1,
+        index,
+      };
+    })
+    .filter((entry) => Number.isFinite(entry.quality) && entry.quality > 0)
+    .sort((a, b) => b.quality - a.quality || a.index - b.index);
+
+  const preferred = accepted[0]?.type;
+  return preferred ? markdownMimeTypes.has(preferred) : false;
+}