refactor(渲染): 移除未使用的锚点变量并格式化代码

移除Sprite::onDraw中未使用的anchor变量，因为锚点处理已由RenderBackend负责
同时调整代码格式以提高可读性

Extra2D/src/scene/sprite.cpp

@@ -148,8 +148,6 @@ void Sprite::onDraw(RenderBackend &renderer) {
   float worldScaleY =
       glm::length(glm::vec2(worldTransform[1][0], worldTransform[1][1]));
 
-  auto anchor = getAnchor();
-
   // 锚点由 RenderBackend 在绘制时处理，这里只传递位置和尺寸
   Rect destRect(worldX, worldY, width * worldScaleX, height * worldScaleY);
 
@@ -167,8 +165,8 @@ void Sprite::onDraw(RenderBackend &renderer) {
   // 从世界变换矩阵中提取旋转角度
   float worldRotation = std::atan2(worldTransform[0][1], worldTransform[0][0]);
 
-  renderer.drawSprite(texture_->getRHITexture(), destRect, srcRect, color_, worldRotation,
-                      flipX_, flipY_);
+  renderer.drawSprite(texture_->getRHITexture(), destRect, srcRect, color_,
+                      worldRotation, flipX_, flipY_);
 }
 
 /**
@@ -224,8 +222,14 @@ void Sprite::generateRenderCommand(std::vector<RenderCommand> &commands,
   RenderCommand cmd;
   cmd.type = RenderCommandType::Sprite;
   cmd.layer = zOrder;
-  cmd.data = SpriteRenderData{texture_->getRHITexture(), destRect, srcRect, color_,
-                               worldRotation, anchor, rhi::BlendState::alphaBlend(), 0};
+  cmd.data = SpriteRenderData{texture_->getRHITexture(),
+                              destRect,
+                              srcRect,
+                              color_,
+                              worldRotation,
+                              anchor,
+                              rhi::BlendState::alphaBlend(),
+                              0};
 
   commands.push_back(std::move(cmd));
 }