feat: URL-sharing system with QR code + share buttons

- buildShareURL(): JSON → pako.deflate → Base64 → URL-Hash
- doPublish(): Share-Modal mit QR-Code, Kopieren, E-Mail, WhatsApp, Native Share
- game.html: loadGameConfig() liest URL-Hash vor localStorage
  - Format 'z:' = komprimiert (pako), 'j:' = plain Base64
  - Fallback auf localStorage (Editor-Test), dann Demo-Config
- CDN: pako 2.1.0 + qrcodejs 1.0.0 (cloudflare)
- Kein Backend nötig: Link ist selbsttragend (~800-1100 Zeichen)
- QR-Code-tauglich für alle normalen Konfigurationen

game.html

@@ -360,6 +360,7 @@ canvas#bgCanvas{
 <div id="transOverlay"></div>
 <div id="toast"></div>
 
+<script src="https://cdnjs.cloudflare.com/ajax/libs/pako/2.1.0/pako.min.js"></script>
 <script>
 /* roundRect polyfill for older browsers */
 if(!CanvasRenderingContext2D.prototype.roundRect){
@@ -374,7 +375,39 @@ if(!CanvasRenderingContext2D.prototype.roundRect){
 }
 
 /* ══════════ CONFIG ══════════ */
-const cfg        = JSON.parse(localStorage.getItem('gameConfig') || '{"name":"Mein Spiel","desc":"Ein tolles Brettspiel!","figure":"robot","background":"space","fieldCount":10,"fields":["snake","flappy","quiz","memory","reaction",null,"snake","quiz",null,""],"rules":{"movement":"dice","fail":"lives","lives":"3","pts":"10"}}');
+// 1. Versuche URL-Hash (geteilter Link), 2. Fallback localStorage, 3. Demo-Config
+function loadGameConfig() {
+  const hash = window.location.hash.slice(1); // '#' entfernen
+  if (hash) {
+    try {
+      if (hash.startsWith('z:')) {
+        // Komprimiert: Base64 → binary → pako.inflate → JSON
+        const b64 = hash.slice(2);
+        const binary = atob(b64);
+        const bytes = new Uint8Array(binary.length);
+        for (let i = 0; i < binary.length; i++) bytes[i] = binary.charCodeAt(i);
+        const json = pako.inflate(bytes, { to: 'string' });
+        return JSON.parse(json);
+      } else if (hash.startsWith('j:')) {
+        // Unkomprimiert Base64
+        return JSON.parse(decodeURIComponent(escape(atob(hash.slice(2)))));
+      }
+    } catch(e) {
+      console.warn('URL-Hash konnte nicht gelesen werden:', e);
+    }
+  }
+  // Fallback: localStorage (vom Editor)
+  try {
+    const stored = localStorage.getItem('gameConfig');
+    if (stored) return JSON.parse(stored);
+  } catch(e) {}
+  // Demo-Config
+  return {name:'Mein Spiel',desc:'Ein tolles Brettspiel!',figure:'robot',
+    background:'space',fieldCount:10,
+    fields:['snake','flappy','quiz','memory','reaction',null,'snake','quiz',null,''],
+    rules:{movement:'dice',fail:'lives',lives:'3',pts:'10'}};
+}
+const cfg = loadGameConfig();
 const fields     = (cfg.fields||[]).map(f=>f||null);
 const fieldCount = cfg.fieldCount || fields.length || 10;
 const rules      = cfg.rules || {movement:'dice',fail:'lives',lives:'3',pts:'10'};