Give each route its own title and canonical, and add robots.txt plus a sitemap.

The root layout was stamping the homepage title and production root onto every page. Routes now supply a page segment through one em-dash template, canonicals follow the request path, and non-production hosts disallow crawlers.

Co-authored-by: Cursor <cursoragent@cursor.com>

app/robots.ts

@@ -0,0 +1,12 @@
+import type { MetadataRoute } from "next";
+import { headers } from "next/headers";
+import { buildRobots, resolveRequestHost } from "../lib/siteMetadata";
+
+export default async function robots(): Promise<MetadataRoute.Robots> {
+  const headerStore = await headers();
+  const host = resolveRequestHost(
+    headerStore.get("x-forwarded-host"),
+    headerStore.get("host"),
+  );
+  return buildRobots(host);
+}