feat(子弹系统): 添加Egg子弹类型及相关资源

添加新的Egg子弹类型，包括脚本、纹理和场景文件。更新Kernyr角色的攻击逻辑以使用Egg子弹。新增篮球和雷电纹理资源及其导入配置。

scripts/Contents/Characters/Kernyr.gd

@@ -45,12 +45,12 @@ func attack(type: int):
 		for i in count:
 			await sprintTo(anchor + Vector2.from_angle(deg_to_rad(i / count * 360.0 - 90)) * radius, 0.5)
 			for bullet in BulletBase.generate(
-				ComponentManager.getBullet("Yangyi"),
+				ComponentManager.getBullet("Egg"),
 				self ,
 				position,
 				0
 			):
-				if bullet is YangyiBullet:
+				if bullet is EggBullet:
 					bullet.look_at(anchor)
 		await TickTool.millseconds(2000)
 		await chargeUp()