feat(game): 添加全套音效系统（背景BGM+7种攻击音+波次/Boss/死亡/建塔音效），纯Web Audio API合成

game/towers/TowerManager.ts

@@ -2,6 +2,7 @@ import type Phaser from 'phaser'
 import { GameManager } from '../GameManager'
 import { getCellSize } from '../mapRenderer'
 import { COFFEE_COST } from '../constants'
+import { AudioEngine } from '../AudioEngine'
 import type { EnemyBase } from '../enemies/EnemyBase'
 import { TowerBase } from './TowerBase'
 import { InternTower } from './InternTower'
@@ -60,6 +61,8 @@ export class TowerManager {
     const tower = this.createTower(type, gridX, gridY)
     this.towers.push(tower)
     this.occupiedCells.add(`${gridX},${gridY}`)
+    // 建塔音效（钉钉消息音）
+    AudioEngine.getInstance().playNotify()
 
     // 监听实习生自毁事件
     if (tower instanceof InternTower) {
@@ -226,6 +229,8 @@ export class TowerManager {
     this.showDestroyEffect(tower)
     tower.destroy()
     this.removeTower(tower)
+    // 塔被摧毁音效
+    AudioEngine.getInstance().playTowerDestroyed()
   }
 
   private showDestroyEffect(tower: TowerBase): void {