feat: add store audio effects and rebalance card stats

- 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.

src/scenes/BootScene.js

@@ -66,6 +66,9 @@ export class BootScene extends Phaser.Scene {
     this.load.audio('sfx_rupture', 'assets/audio/fx/rupture.mp3');
     this.load.audio('sfx_rupture_effect', 'assets/audio/fx/rupture-effect.mp3');
     this.load.audio('sfx_fortify', 'assets/audio/fx/fortify.mp3');
+    this.load.audio('sfx_store_buy', 'assets/audio/fx/buy.mp3');
+    this.load.audio('sfx_store_card', 'assets/audio/fx/card.mp3');
+    this.load.audio('sfx_store_card_bonus', 'assets/audio/fx/card-bonus.mp3');
 
     this.load.audio('music_main_menu', 'assets/audio/music/main_menu.mp3');
 

src/scenes/StoreScene.js

@@ -234,6 +234,8 @@ export class StoreScene extends Phaser.Scene {
       return;
     }
 
+    this.sound.play('sfx_store_buy', { volume: 0.8 });
+
     // Add cards to collection
     cards.forEach(card => SaveManager.addCard(this.save, card.id));
     this.registry.set('save', this.save);
@@ -347,6 +349,7 @@ export class StoreScene extends Phaser.Scene {
       ease: 'Quad.In',
       onComplete: () => {
         back.setVisible(false);
+        this.sound.play('sfx_store_card', { volume: 0.8 });
 
         // Show front, flip in
         cardObj.setAlpha(1);
@@ -356,6 +359,11 @@ export class StoreScene extends Phaser.Scene {
           duration: 150,
           ease: 'Quad.Out',
           onComplete: () => {
+            // Bonus sound for rare, epic, legendary
+            if (['rare', 'epic', 'legendary'].includes(card.rarity)) {
+              this.sound.play('sfx_store_card_bonus', { volume: 0.9 });
+            }
+
             // Pop effect
             this.tweens.add({
               targets: cardObj,