fix: Improve texture upload handling and caching logic

- Simplified caching logic by removing unnecessary nil check before setting cache.
- Enhanced error handling in texture upload process to return the original texture object if fetching the uploader information fails or returns nil.

internal/service/texture_service.go

@@ -87,9 +87,7 @@ func (s *textureService) GetByID(ctx context.Context, id int64) (*model.Texture,
 	}
 
 	// 存入缓存（异步）
-	if texture2 != nil {
 	s.cache.SetAsync(context.Background(), cacheKey, texture2, s.cache.Policy.TextureTTL)
-	}
 
 	return texture2, nil
 }
@@ -382,7 +380,16 @@ func (s *textureService) UploadTexture(ctx context.Context, uploaderID int64, na
 	s.cacheInv.BatchInvalidate(ctx, fmt.Sprintf("texture:user:%d:*", uploaderID))
 
 	// 重新查询以预加载 Uploader 关联
-	return s.textureRepo.FindByID(ctx, texture.ID)
+	textureWithUploader, err := s.textureRepo.FindByID(ctx, texture.ID)
+	if err != nil {
+		// 如果查询失败，返回原始创建的 texture 对象（虽然可能没有 Uploader 信息）
+		return texture, nil
+	}
+	if textureWithUploader == nil {
+		// 如果查询返回 nil（极端情况，如数据库复制延迟），返回原始创建的 texture 对象
+		return texture, nil
+	}
+	return textureWithUploader, nil
 }
 
 // parseTextureTypeInternal 解析材质类型