feat: Add backend storage for cross-domain player state synchronization

- Add PlayerState model to database schema for storing game states
- Create player identifier system (UUID-based) for cross-domain sync
- Implement API endpoints for loading/saving player states
- Refactor gameState hook to use backend storage with localStorage fallback
- Support synchronization between hoerdle.de and hördle.de
- Migration automatically runs on Docker container start

components/Game.tsx

@@ -39,7 +39,7 @@ const DEFAULT_UNLOCK_STEPS = [2, 4, 7, 11, 16, 30, 60];
 export default function Game({ dailyPuzzle, genre = null, isSpecial = false, maxAttempts = 7, unlockSteps = DEFAULT_UNLOCK_STEPS }: GameProps) {
     const t = useTranslations('Game');
     const locale = useLocale();
-    const { gameState, statistics, addGuess, giveUp, addReplay, addYearBonus, skipYearBonus } = useGameState(genre, maxAttempts);
+    const { gameState, statistics, addGuess, giveUp, addReplay, addYearBonus, skipYearBonus } = useGameState(genre, maxAttempts, isSpecial);
     const [hasWon, setHasWon] = useState(false);
     const [hasLost, setHasLost] = useState(false);
     const [shareText, setShareText] = useState(`🔗 ${t('share')}`);