- Added new audio files for store interactions: `buy.mp3`, `card.mp3`, and `card-bonus.mp3`.
- Updated `BootScene` to preload the new sound effects.
- Implemented sound triggers in `StoreScene`:
- Plays `sfx_store_buy` upon purchasing cards.
- Plays `sfx_store_card` when revealing a card.
- Plays `sfx_store_card_bonus` for rare, epic, and legendary cards.
- Rebalanced `data/cards.json` to adjust game mechanics:
- Set `attack` to `0` for all legendary card levels.
- Reduced `health` values across all card tiers.
- Standardized `delay` values to `0` or `1` for most cards, removing high delay values.
