feat(annotation): 添加文本分段标注功能

- 引入文本分割器实现长文本按200字符自动分段
- 增加分段状态管理和段落导航界面
- 支持按段落保存和加载标注数据
- 实现分段模式下的标注状态跟踪
- 扩展API接口支持段落索引参数
- 添加分段相关的数据模型定义

frontend/src/pages/DataAnnotation/annotation.api.ts

@@ -61,14 +61,22 @@ export function listEditorTasksUsingGet(projectId: string, params?: any) {
   return get(`/api/annotation/editor/projects/${projectId}/tasks`, params);
 }
 
-export function getEditorTaskUsingGet(projectId: string, fileId: string) {
-  return get(`/api/annotation/editor/projects/${projectId}/tasks/${fileId}`);
+export function getEditorTaskUsingGet(
+  projectId: string,
+  fileId: string,
+  params?: { segmentIndex?: number }
+) {
+  return get(`/api/annotation/editor/projects/${projectId}/tasks/${fileId}`, params);
 }
 
 export function upsertEditorAnnotationUsingPut(
   projectId: string,
   fileId: string,
-  data: any
+  data: {
+    annotation: any;
+    expectedUpdatedAt?: string;
+    segmentIndex?: number;
+  }
 ) {
   return put(`/api/annotation/editor/projects/${projectId}/tasks/${fileId}/annotation`, data);
 }