Donate stranka: PAY by square QR s vyberom sumy

Linka Na kavu v hlavicke lobby vedie na /donate. QR sa generuje
dynamicky (balicek bysquare) pre presety 1/2/5 EUR alebo vlastnu sumu;
IBAN sa da skopirovat do schranky. Navstevy loguje existujuci
pageview beacon.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

frontend/src/App.tsx

@@ -9,6 +9,7 @@ import Lobby from './pages/Lobby';
 import GameTable from './pages/GameTable';
 import Auth from './pages/Auth';
 import History from './pages/History';
+import Donate from './pages/Donate';
 
 // Admin pulls in recharts — lazy-load it so players never download that chunk.
 const AdminLayout = lazy(() => import('./pages/admin/AdminLayout'));
@@ -107,6 +108,7 @@ function AppInner() {
           <Route path="/auth" element={<Auth />} />
           <Route path="/" element={<GameList />} />
           <Route path="/history" element={<History />} />
+          <Route path="/donate" element={<Donate />} />
           <Route path="/lobby/:gid" element={<Lobby />} />
           <Route path="/game/:gid" element={<GameTable />} />
           <Route path="/admin" element={<AdminLayout />}>