fix(game): 修复底部塔面板不可见问题，改用React层实现，并用AI素材替换Graphics像素块

game/enemies/OldEmployee.ts

@@ -4,35 +4,12 @@ import { getRandomQuote } from '../data/quotes'
 
 export class OldEmployee extends EnemyBase {
   constructor(scene: Phaser.Scene, pathPoints: PathPoint[]) {
-    super(scene, pathPoints, 150, 50, 8, 30)
+    super(scene, pathPoints, 150, 50, 8, 30, 'enemy-old')
     this.shieldCount = 3
-    this.drawSprite()
+    // 老员工图片稍大
+    const scale = Math.min(this.cellW, this.cellH) / 128 * 0.9
+    this.imageSprite.setScale(scale)
   }
 
-  drawSprite(): void {
-    if (!this.sprite) return
-    this.sprite.clear()
-    // 大蓝方块
-    this.sprite.fillStyle(0x93c5fd, 1)
-    this.sprite.fillRect(-10, -10, 20, 20)
-    // 护盾外框（金色）
-    this.sprite.lineStyle(2, 0xfbbf24, 0.8)
-    this.sprite.strokeRect(-12, -12, 24, 24)
-    this.sprite.setDepth(10)
-    this.sprite.setPosition(this.x, this.y)
-  }
-
-  override drawHealthBar(): void {
-    super.drawHealthBar()
-    // 绘制护盾数量标记
-    if (!this.healthBar) return
-    for (let i = 0; i < this.shieldCount; i++) {
-      this.healthBar.fillStyle(0xfbbf24, 1)
-      this.healthBar.fillRect(this.x - 15 + i * 11, this.y - 28, 8, 4)
-    }
-  }
-
-  getQuote(): string {
-    return getRandomQuote('OldEmployee')
-  }
+  getQuote(): string { return getRandomQuote('OldEmployee') }
 }