perf: 优化故事项查询性能并调整字段映射

删除 Service 层循环查询图片的逻辑，改为通过 SQL 关联或后续批量处理以减少数据库 IO 开销。同时在 Mapper 中完善字段选择，增加 id、type、status 等必要字段，并移除冗余的 update_time。

timeline-story-service/src/main/java/com/timeline/story/service/impl/StoryItemServiceImpl.java

@@ -40,15 +40,6 @@ public class StoryItemServiceImpl implements StoryItemService {
         }
 
         List<StoryItemVo> list = storyItemMapper.selectStoryItemByStoryInstanceId(params);
-
-        // 填充图片信息
-        if (list != null && !list.isEmpty()) {
-            for (StoryItemVo item : list) {
-                List<String> images = storyItemMapper.selectImagesByItemId(item.getInstanceId());
-                item.setImages(images);
-            }
-        }
-
         PageInfo<StoryItemVo> pageInfo = new PageInfo<>(list);
 
         Map<String, Object> result = new HashMap<>();

timeline-story-service/src/main/resources/com/timeline/story/dao/StoryItemMapper.xml

@@ -41,16 +41,19 @@
     </select>
     <select id="selectStoryItemByStoryInstanceId" resultType="com.timeline.story.vo.StoryItemVo">
         SELECT
-            instance_id,
+            si.id,
+            si.instance_id,
             si.description,
             si.location,
-            title,
-            story_instance_id,
+            si.title,
+            si.story_instance_id,
             si.master_item_id,
             si.share_id,
             si.cover,
+            si.type,
+            si.status,
+            si.is_delete,
             si.story_item_time as story_item_time,
-            si.update_time,
             si.create_id AS create_id,
             si.create_time AS create_time,
             u1.username AS create_name,