feat: 添加新角色Kernyr和子弹Yangyi及相关资源

添加新角色Kernyr及其相关资源文件，包括角色脚本、场景和贴图
添加新子弹类型Yangyi及其相关资源文件，包括子弹脚本、场景和贴图
修改Wave.gd添加Kernyr作为测试波次
调整QKSword.gd和Parrier.gd的数值效果
扩展Bullet.gd的selfRotate方法支持仅旋转贴图

scripts/Contents/AIPresets/Bullet.gd

@@ -15,7 +15,8 @@ static func trace(bullet: BulletBase, target: Vector2, speed: float):
 	)
 static func faceToMouse(bullet: BulletBase):
 	bullet.rotation = bullet.position.angle_to_point(bullet.get_global_mouse_position())
-static func selfRotate(bullet: BulletBase, speed: float):
-	bullet.rotation += deg_to_rad(speed)
+static func selfRotate(bullet: BulletBase, speed: float, justTexture: bool = false):
+	var target: Node2D = bullet.texture as Node2D if justTexture else bullet as Node2D
+	target.rotation += deg_to_rad(speed)
 static func lerpPosition(bullet: BulletBase, target: Vector2, speed: float):
 	bullet.position = bullet.position.lerp(target, speed)