fix(annotation): 修复导出服务中的重复数据处理逻辑

- 移除了重复的else分支代码块
- 修复了分段索引键不存在时的数据处理流程
- 简化了列表类型分段的处理逻辑
- 消除了重复的数据添加操作

runtime/datamate-python/app/module/annotation/service/export.py

@@ -265,8 +265,6 @@ class AnnotationExportService:
                             if SEGMENT_INDEX_KEY not in normalized and SEGMENT_INDEX_FALLBACK_KEY not in normalized:
                                 normalized[SEGMENT_INDEX_KEY] = int(key) if str(key).isdigit() else key
                             results.append(normalized)
-                        else:
-                            results.append({"value": item, SEGMENT_INDEX_KEY: key})
             elif isinstance(segments, list):
                 for idx, segment in enumerate(segments):
                     if not isinstance(segment, dict):
@@ -281,8 +279,6 @@ class AnnotationExportService:
                             if SEGMENT_INDEX_KEY not in normalized and SEGMENT_INDEX_FALLBACK_KEY not in normalized:
                                 normalized[SEGMENT_INDEX_KEY] = segment_index
                             results.append(normalized)
-                        else:
-                            results.append({"value": item, SEGMENT_INDEX_KEY: segment_index})
             return results
         result = annotation.get(SEGMENT_RESULT_KEY)
         return result if isinstance(result, list) else []