feat(points): balance, history and shop page

Add /points page with wallet balance, shop grouped by slot and ledger
history with game names. The wallet loads once in PreferencesContext after
login, so the header shows a balance chip and the link. Premium accents
gold and teal override the free accent while equipped. German and English.

src/App.jsx

@@ -20,6 +20,7 @@ import WishlistPage from './pages/WishlistPage.jsx';
 import PlayNextPage from './pages/PlayNextPage.jsx';
 import StatsPage from './pages/StatsPage.jsx';
 import ImportPage from './pages/ImportPage.jsx';
+import PointsPage from './pages/PointsPage.jsx';
 import PublicProfilePage from './pages/PublicProfilePage.jsx';
 import AppHeader from './components/AppHeader.jsx';
 import RequireSession from './components/RequireSession.jsx';
@@ -74,6 +75,7 @@ function App() {
                             <Route path="/play-next" element={<PlayNextPage/>}/>
                             <Route path="/stats" element={<StatsPage/>}/>
                             <Route path="/import" element={<ImportPage/>}/>
+                            <Route path="/points" element={<PointsPage/>}/>
                             <Route path="/settings" element={<SettingsPage/>}/>
                             <Route path="/whats-new" element={<WhatsNewPage/>}/>
                             <Route path="/welcome" element={<WelcomePage/>}/>