feat(战斗系统): 增强KukeMC及其子体的战斗能力

- 为KukeChild添加重型紫水晶攻击方式并调整治疗量
- 修改KukeMC的攻击逻辑，在低血量时才会召唤子体
- 调整重型紫水晶的属性和动画效果
- 增加子弹生成时的初始速度和加速度

scripts/Contents/Bullets/BossAttack/KukeMC/HeavyCrystal.gd

@@ -5,13 +5,16 @@ extends BulletBase
 
 var readyTime: float = 1000
 
+func register():
+	speed = -10
 func spawn():
 	trail.emitting = false
 func ai():
 	if timeLived() < readyTime:
+		PresetBulletAI.lockLauncher(self, launcher, true)
 		rotation = launcher.position.angle_to_point(launcher.currentFocusedBoss.position)
 	else:
 		PresetBulletAI.forward(self, rotation)
-		speed += 1
+		speed += 2
 		trail.emitting = true
 		track.visible = false