feat(会话)：历史学习记录折叠面板（残片/报告分页+搜索）

StartTask.vue 新增「📚 历史学习记录」折叠区域：
- 默认折叠，点击标题展开
- 支持残片/报告两个 tab 切换
- 搜索框带 300ms 防抖，对内容 LIKE 搜索
- 分页每页 10 条
- 每条记录前标注所属 sessionNum，与当前会话内容明确区分
- 展示 v-loading 和 el-empty 两种状态

后端新增两个分页接口（上一 commit）：
- GET /study-sessions/tasks/{taskNum}/fragments
- GET /study-sessions/tasks/{taskNum}/reports

src/api/studySessions.ts

@@ -36,3 +36,17 @@ export const upsertExpectation = (sessionNum: string, description: string) => {
 export const getReportDraft = (sessionNum: string) => {
     return request.get(`/study-sessions/${sessionNum}/report-draft`);
 };
+
+/** 分页查询任务的历史残片 */
+export const getTaskFragments = (taskNum: string, page: number, size: number, keyword?: string) => {
+    const params: Record<string, any> = { page, size };
+    if (keyword) params.keyword = keyword;
+    return request.get(`/study-sessions/tasks/${taskNum}/fragments`, params);
+};
+
+/** 分页查询任务的历史报告 */
+export const getTaskReports = (taskNum: string, page: number, size: number, keyword?: string) => {
+    const params: Record<string, any> = { page, size };
+    if (keyword) params.keyword = keyword;
+    return request.get(`/study-sessions/tasks/${taskNum}/reports`, params);
+};

src/components/StartTask.vue

@@ -11,7 +11,7 @@ import {
 } from "@/api/studySessions";
 import { useStudyFragment } from "@/components/composables/fragment";
 import { getFragmentsBySession, updateFragments } from "@/api/reportFragments";
-import { getExpectation, getReportDraft, upsertExpectation } from "@/api/studySessions";
+import { getExpectation, getReportDraft, getTaskFragments, getTaskReports, upsertExpectation } from "@/api/studySessions";
 import router from "@/router";
 
 const {
@@ -44,6 +44,77 @@ const editingFragmentId = ref<number | null>(null);
 const editFragmentContent = ref("");
 const savingFragment = ref(false);
 
+// 历史学习记录
+const showHistory = ref(false);
+const historyTab = ref("fragments");
+const historyKeyword = ref("");
+let historyDebounce: ReturnType<typeof setTimeout> | null = null;
+const loadingHistory = ref(false);
+const historyFragments = ref<any[]>([]);
+const fragmentsTotal = ref(0);
+const fragmentsPage = ref(1);
+const historyReports = ref<any[]>([]);
+const reportsTotal = ref(0);
+const reportsPage = ref(1);
+const PAGE_SIZE = 10;
+
+const loadHistoryFragments = async () => {
+  loadingHistory.value = true;
+  try {
+    const res = await getTaskFragments(taskNum, fragmentsPage.value, PAGE_SIZE, historyKeyword.value || undefined);
+    const data = res?.data;
+    historyFragments.value = data?.records || [];
+    fragmentsTotal.value = data?.total || 0;
+  } catch {
+    historyFragments.value = [];
+    fragmentsTotal.value = 0;
+  } finally {
+    loadingHistory.value = false;
+  }
+};
+
+const loadHistoryReports = async () => {
+  loadingHistory.value = true;
+  try {
+    const res = await getTaskReports(taskNum, reportsPage.value, PAGE_SIZE, historyKeyword.value || undefined);
+    const data = res?.data;
+    historyReports.value = data?.records || [];
+    reportsTotal.value = data?.total || 0;
+  } catch {
+    historyReports.value = [];
+    reportsTotal.value = 0;
+  } finally {
+    loadingHistory.value = false;
+  }
+};
+
+const searchHistory = () => {
+  if (historyDebounce) clearTimeout(historyDebounce);
+  historyDebounce = setTimeout(() => {
+    fragmentsPage.value = 1;
+    reportsPage.value = 1;
+    if (historyTab.value === "fragments") loadHistoryFragments();
+    else loadHistoryReports();
+  }, 300);
+};
+
+const onHistoryTabChange = () => {
+  fragmentsPage.value = 1;
+  reportsPage.value = 1;
+  if (historyTab.value === "fragments") loadHistoryFragments();
+  else loadHistoryReports();
+};
+
+const onFragmentsPageChange = (p: number) => {
+  fragmentsPage.value = p;
+  loadHistoryFragments();
+};
+
+const onReportsPageChange = (p: number) => {
+  reportsPage.value = p;
+  loadHistoryReports();
+};
+
 const route = useRoute();
 const taskNum = route.params.taskNum as string;
 
@@ -552,6 +623,41 @@ onUnmounted(() => {
         </template>
       </div>
     </article>
+<!-- 历史学习记录 -->
+    <article class="surface-card history-card">
+      <div class="history-header" @click="showHistory = !showHistory">
+        <div class="history-header-left">
+          <span class="history-toggle">{{ showHistory ? "▾" : "▸" }}</span>
+          <h3>📚 历史学习记录</h3>
+        </div>
+        <el-tag size="small" type="info" effect="plain">展开后查看该任务全部残片与报告</el-tag>
+      </div>
+      <template v-if="showHistory">
+        <el-input v-model="historyKeyword" placeholder="搜索历史内容…" clearable class="history-search" @input="searchHistory" @clear="searchHistory" />
+        <el-tabs v-model="historyTab" @tab-change="onHistoryTabChange" class="history-tabs">
+          <el-tab-pane label="学习残片" name="fragments">
+            <div v-loading="loadingHistory" class="history-list">
+              <div v-for="item in historyFragments" :key="item.id" class="history-item">
+                <span class="session-tag">{{ item.sessionNum }}</span>
+                <span class="history-content">{{ item.content }}</span>
+              </div>
+              <el-empty v-if="!loadingHistory && historyFragments.length === 0" description="暂未找到匹配的残片" :image-size="48" />
+            </div>
+            <el-pagination v-if="fragmentsTotal > 10" small layout="prev, pager, next" :total="fragmentsTotal" :page-size="10" :current-page="fragmentsPage" @current-change="onFragmentsPageChange" background />
+          </el-tab-pane>
+          <el-tab-pane label="学习报告" name="reports">
+            <div v-loading="loadingHistory" class="history-list">
+              <div v-for="item in historyReports" :key="item.id" class="history-item report-item">
+                <span class="session-tag">{{ item.sessionNum }}</span>
+                <p class="history-content">{{ item.content }}</p>
+              </div>
+              <el-empty v-if="!loadingHistory && historyReports.length === 0" description="暂未找到匹配的报告" :image-size="48" />
+            </div>
+            <el-pagination v-if="reportsTotal > 10" small layout="prev, pager, next" :total="reportsTotal" :page-size="10" :current-page="reportsPage" @current-change="onReportsPageChange" background />
+          </el-tab-pane>
+        </el-tabs>
+      </template>
+    </article>
   </section>
 
   <el-dialog v-model="fragmentsDialogVisible" title="生成学习残片" width="520px">