feat(annotation): 优化文本标注分段功能实现

- 新增 getEditorTaskSegmentsUsingGet 接口用于获取任务分段信息
- 移除 SegmentInfo 中的 text、start、end 字段，精简数据结构
- 添加 EditorTaskSegmentsResponse 类型定义用于分段摘要响应
- 实现服务端 get_task_segments 方法，支持分段信息查询
- 重构前端组件缓存机制，使用 segmentSummaryFileRef 管理分段状态
- 优化分段构建逻辑，提取 _build_segment_contexts 公共方法
- 调整后端 _build_text_task 方法中的分段处理流程
- 更新 API 类型定义，统一 RequestParams 和 RequestPayload 类型

frontend/src/pages/DataAnnotation/Annotate/LabelStudioTextEditor.tsx

@@ -6,6 +6,7 @@ import { useNavigate, useParams } from "react-router";
 import {
   getEditorProjectInfoUsingGet,
   getEditorTaskUsingGet,
+  getEditorTaskSegmentsUsingGet,
   listEditorTasksUsingGet,
   upsertEditorAnnotationUsingPut,
 } from "../annotation.api";
@@ -38,9 +39,6 @@ type LsfMessage = {
 
 type SegmentInfo = {
   idx: number;
-  text: string;
-  start: number;
-  end: number;
   hasAnnotation: boolean;
   lineIndex: number;
   chunkIndex: number;
@@ -66,10 +64,16 @@ type EditorTaskPayload = {
 type EditorTaskResponse = {
   task?: EditorTaskPayload;
   segmented?: boolean;
-  segments?: SegmentInfo[];
+  totalSegments?: number;
   currentSegmentIndex?: number;
 };
 
+type EditorTaskSegmentsResponse = {
+  segmented?: boolean;
+  segments?: SegmentInfo[];
+  totalSegments?: number;
+};
+
 type EditorTaskListResponse = {
   content?: EditorTaskListItem[];
   totalElements?: number;
@@ -288,6 +292,7 @@ export default function LabelStudioTextEditor() {
   const segmentStatsCacheRef = useRef<Record<string, SegmentStats>>({});
   const segmentStatsSeqRef = useRef(0);
   const segmentStatsLoadingRef = useRef<Set<string>>(new Set());
+  const segmentSummaryFileRef = useRef<string>("");
 
   const [loadingProject, setLoadingProject] = useState(true);
   const [loadingTasks, setLoadingTasks] = useState(false);
@@ -358,9 +363,7 @@ export default function LabelStudioTextEditor() {
     if (segmentStatsCacheRef.current[fileId] || segmentStatsLoadingRef.current.has(fileId)) return;
     segmentStatsLoadingRef.current.add(fileId);
     try {
-      const resp = (await getEditorTaskUsingGet(projectId, fileId, {
-        segmentIndex: 0,
-      })) as ApiResponse<EditorTaskResponse>;
+      const resp = (await getEditorTaskSegmentsUsingGet(projectId, fileId)) as ApiResponse<EditorTaskSegmentsResponse>;
       if (segmentStatsSeqRef.current !== seq) return;
       const data = resp?.data;
       if (!data?.segmented) return;
@@ -591,20 +594,38 @@ export default function LabelStudioTextEditor() {
       if (seq !== initSeqRef.current) return;
 
       // 更新分段状态
-      const segmentIndex = data?.segmented
+      const isSegmented = !!data?.segmented;
+      const segmentIndex = isSegmented
         ? resolveSegmentIndex(data.currentSegmentIndex) ?? 0
         : undefined;
-      if (data?.segmented) {
-        const stats = buildSegmentStats(data.segments);
+      if (isSegmented) {
+        let nextSegments: SegmentInfo[] = [];
+        if (segmentSummaryFileRef.current === fileId && segments.length > 0) {
+          nextSegments = segments;
+        } else {
+          try {
+            const segmentResp = (await getEditorTaskSegmentsUsingGet(projectId, fileId)) as ApiResponse<EditorTaskSegmentsResponse>;
+            if (seq !== initSeqRef.current) return;
+            const segmentData = segmentResp?.data;
+            if (segmentData?.segmented) {
+              nextSegments = Array.isArray(segmentData.segments) ? segmentData.segments : [];
+            }
+          } catch (e) {
+            console.error(e);
+          }
+        }
+        const stats = buildSegmentStats(nextSegments);
         setSegmented(true);
-        setSegments(data.segments || []);
+        setSegments(nextSegments);
         setCurrentSegmentIndex(segmentIndex ?? 0);
         updateSegmentStatsCache(fileId, stats);
+        segmentSummaryFileRef.current = fileId;
       } else {
         setSegmented(false);
         setSegments([]);
         setCurrentSegmentIndex(0);
         updateSegmentStatsCache(fileId, null);
+        segmentSummaryFileRef.current = fileId;
       }
 
       const taskData = {
@@ -664,7 +685,7 @@ export default function LabelStudioTextEditor() {
     } finally {
       if (seq === initSeqRef.current) setLoadingTaskDetail(false);
     }
-  }, [iframeReady, message, postToIframe, project, projectId, updateSegmentStatsCache]);
+  }, [iframeReady, message, postToIframe, project, projectId, segments, updateSegmentStatsCache]);
 
   const advanceAfterSave = useCallback(async (fileId: string, segmentIndex?: number) => {
     if (!fileId) return;
@@ -979,6 +1000,7 @@ export default function LabelStudioTextEditor() {
     setSegmented(false);
     setSegments([]);
     setCurrentSegmentIndex(0);
+    segmentSummaryFileRef.current = "";
     savedSnapshotsRef.current = {};
     segmentStatsSeqRef.current += 1;
     segmentStatsCacheRef.current = {};