refactor(bullet): 修复子弹切割时的速度缩放逻辑

1. 修正Volcano子弹动画速度计算改为直接修改animator.speed_scale
2. 调整Volcano子弹发射速度倍率从0.9倍改为原0.75倍
3. 优化Volcano子弹粒子发射速度从300改为150
4. 调整MuyangDog的fieldValues并添加点击重建属性
5. 修复Volcano动画轨迹的多余关键帧与modulate显示逻辑

scripts/Statemachine/BulletBase.gd

@@ -131,13 +131,13 @@ func setupCuttable(cutSpeed: float):
 		func(body):
 			var entity = EntityTool.fromHurtbox(body)
 			if entity:
-				speedScale *= cutSpeed
+				animator.speed_scale *= cutSpeed
 	)
 	area_exited.connect(
 		func(body):
 			var entity = EntityTool.fromHurtbox(body)
 			if entity:
-				speedScale /= cutSpeed
+				animator.speed_scale /= cutSpeed
 	)
 func getDamage():
 	return baseDamage * damageMultipliers[usingDamageMultiplier]