SEO: Canonicals/OG auf allen Seiten, WebP, Caching, www-Redirect

- alle Unterseiten: Canonical-Tags; techday/gamejam zusaetzlich Open Graph
- techday: Event-JSON-LD (27. Mai 2026, HubWerk01 Bruchsal)
- mITapp-Screenshots als WebP (1,6 MB -> 65 KB) mit width/height/lazy
- dediziertes OG-Bild 1200x630 (Logo + Tagline) fuer Start & GameJam
- server.js: 301 www -> non-www, /index.html -> /, statische Assets
  1 Jahr immutable cachen (HTML weiter no-cache), .webp MIME
- CSS/JS ueberall versioniert (?v=20260610)
- sitemap: lastmod ergaenzt, noindex-Seiten (Impressum/Datenschutz) entfernt

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

server.js

@@ -112,6 +112,7 @@ const MIME = {
   ".png": "image/png",
   ".jpg": "image/jpeg",
   ".jpeg": "image/jpeg",
+  ".webp": "image/webp",
   ".ico": "image/x-icon",
   ".json": "application/json; charset=utf-8",
   ".woff2": "font/woff2",
@@ -174,6 +175,20 @@ function saveLead(lead) {
 /* ---------- Statische Dateien ---------- */
 function serveStatic(req, res) {
   let urlPath = decodeURIComponent(req.url.split("?")[0]);
+
+  /* SEO: kanonischer Host (www -> non-www) und /index.html -> / */
+  const host = (req.headers.host || "").toLowerCase();
+  if (host === "www.tool-ctrl.de") {
+    res.writeHead(301, { Location: "https://tool-ctrl.de" + req.url });
+    res.end();
+    return;
+  }
+  if (urlPath === "/index.html") {
+    res.writeHead(301, { Location: "/" });
+    res.end();
+    return;
+  }
+
   if (urlPath === "/") urlPath = "/index.html";
 
   /* Path-Traversal verhindern */
@@ -195,9 +210,13 @@ function serveStatic(req, res) {
       return;
     }
     const ext = path.extname(filePath).toLowerCase();
+    /* HTML immer frisch, statische Assets lange cachen (Versionierung via ?v=) */
+    const cacheControl = ext === ".html"
+      ? "no-cache"
+      : "public, max-age=31536000, immutable";
     res.writeHead(200, {
       "Content-Type": MIME[ext] || "application/octet-stream",
-      "Cache-Control": "no-cache"
+      "Cache-Control": cacheControl
     });
     fs.createReadStream(filePath).pipe(res);
   });