Make the Kevin page the home page, move Merz to /merz

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

next.config.mjs

@@ -2,6 +2,7 @@
 export default {
   output: "standalone",
   async rewrites() {
-    return [{ source: "/kevin", destination: "/kevin.html" }];
+    // The Kevin page is the home page; the Merz site lives at /merz
+    return { beforeFiles: [{ source: "/", destination: "/kevin.html" }] };
   },
 };