fix(video): 处理空imgSource情况- 添加空值检查以避免保存空source记录

- 记录警告日志当imgSource为空时- 返回false以跳过无效处理流程

src/main/java/com/ycwl/basic/task/VideoPieceGetter.java

@@ -318,6 +318,10 @@ public class VideoPieceGetter {
             }
             if (source == null) {
                 SourceEntity imgSource = sourceMapper.findBySampleId(faceSampleId);
+                if (imgSource == null) {
+                    log.warn("imgSource为null，跳过保存source记录, faceSampleId: {}", faceSampleId);
+                    return false;
+                }
                 SourceEntity sourceEntity = new SourceEntity();
                 sourceEntity.setId(SnowFlakeUtil.getLongId());
                 sourceEntity.setCreateTime(baseTime);