Frontend: hamburger menu v hlavicke na mobile

Hlavicka GameListu sa na uzkych displejoch nezmestila do jedneho
riadku. Pod sm: breakpointom sa polozky zbalia do dropdownu.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

frontend/src/pages/GameList.tsx

@@ -3,6 +3,7 @@ import { useNavigate } from 'react-router-dom';
 import { useGameStore } from '../store/gameStore';
 import { emit, socket, setAuthToken } from '../lib/socket';
 import { trackEvent } from '../lib/track';
+import HeaderMenu from '../components/HeaderMenu';
 import NameModal from '../components/NameModal';
 import RulesModal from '../components/RulesModal';
 
@@ -33,18 +34,12 @@ export default function GameList() {
     <div className="max-w-md mx-auto p-4 pt-8 min-h-screen">
       <div className="flex items-center justify-between mb-6">
         <h1 className="font-serif text-2xl text-gold tracking-wide">Bridžik</h1>
-        <div className="flex items-center gap-3 text-sm">
-          <span className="text-green-dim">{account?.username}</span>
-          <button onClick={() => navigate('/history')} className="text-gold hover:text-gold-bright">
-            História
-          </button>
-          <button onClick={() => navigate('/donate')} className="text-gold hover:text-gold-bright">
-            Na kávu
-          </button>
-          <button onClick={handleLogout} className="text-green-dim hover:text-gold">
-            Odhlásiť
-          </button>
-        </div>
+        <HeaderMenu
+          username={account?.username}
+          onHistory={() => navigate('/history')}
+          onDonate={() => navigate('/donate')}
+          onLogout={handleLogout}
+        />
       </div>
 
       <div className="flex flex-col gap-3 mb-6">