SEO: Favicon 96x96, GameJam-Uploads noindex, og:image-Metadaten

- Favicon aus Emblem neu in 96x96 generiert (Google-SERP braucht min. 48x48),
  Favicon-Links versioniert
- /gamejam-games/: X-Robots-Tag noindex + robots.txt Disallow (Fremdcontent)
- og:image:width/height/alt auf Start, TechDay und GameJam

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

server.js

@@ -214,10 +214,15 @@ function serveStatic(req, res) {
     const cacheControl = ext === ".html"
       ? "no-cache"
       : "public, max-age=31536000, immutable";
-    res.writeHead(200, {
+    const headers = {
       "Content-Type": MIME[ext] || "application/octet-stream",
       "Cache-Control": cacheControl
-    });
+    };
+    /* Hochgeladene GameJam-Spiele nicht indexieren (Fremdcontent) */
+    if (urlPath.startsWith("/gamejam-games/")) {
+      headers["X-Robots-Tag"] = "noindex";
+    }
+    res.writeHead(200, headers);
     fs.createReadStream(filePath).pipe(res);
   });
 }