feat: improve audit exports and admin analytics

2026-08-25 18:49:56 +08:00
parent 910e67bd89
commit 5740bd26e7
55 changed files with 1654 additions and 269 deletions
--- a/ai_knowledge_base_v2/apps/admin-web/src/App.vue
+++ b/ai_knowledge_base_v2/apps/admin-web/src/App.vue
@@ -1137,8 +1137,8 @@ async function clearFeishuCache() {
          :can-detail="can('feedback.detail')"
          :can-export="can('feedback.export')"
        />
-        <UserBehaviorAnalysisView v-if="activeMenu === 'behavior'" />
-        <RecordAuditView v-if="activeMenu === 'records'" />
+        <UserBehaviorAnalysisView v-if="activeMenu === 'behavior'" :can-export="can('behavior.export')" />
+        <RecordAuditView v-if="activeMenu === 'records'" :can-export="can('records.export')" />
        <AdminManagementView v-if="activeMenu === 'admins'" />
      </section>
    </section>
--- a/ai_knowledge_base_v2/apps/admin-web/src/components/AgentBatchTestPanel.vue
+++ b/ai_knowledge_base_v2/apps/admin-web/src/components/AgentBatchTestPanel.vue
@@ -5,6 +5,7 @@ import { computed, onBeforeUnmount, onMounted, reactive, ref } from "vue";
 import { api } from "../services/api";
 import type { AgentBatchItem, AgentBatchJob, AgentBatchJobDetail } from "../types/api";
 import AdminPagination from "./AdminPagination.vue";
+import { formatDateTime } from "../utils/dateTime";

 const props = defineProps<{
  config: Record<string, unknown>;
@@ -165,10 +166,6 @@ function executionLabel(job: AgentBatchJob) {
  return job.executionMode === "concurrent" ? `并发 · ${job.concurrencyLimit} 路` : "逐条串行";
 }

-function formatDate(value?: string | null) {
-  return value ? new Date(value).toLocaleString("zh-CN", { hour12: false }) : "—";
-}
-
 function itemDuration(item: AgentBatchItem) {
  return item.durationMs == null ? "—" : `${(item.durationMs / 1000).toFixed(1)} 秒`;
 }
@@ -213,7 +210,7 @@ function errorMessage(error: unknown, fallback: string) {

    <div class="agent-batch-list-head"><div><h4>测试记录</h4><p>任务在后台执行，离开页面不会中断。</p></div><el-button :loading="loading" @click="loadJobs()">刷新</el-button></div>
    <el-table v-loading="loading" :data="jobs" stripe>
-      <el-table-column label="任务" min-width="190"><template #default="{ row }"><strong>{{ row.name }}</strong><small class="agent-batch-cell-note">#{{ row.id }} · {{ formatDate(row.createdAt) }}</small></template></el-table-column>
+      <el-table-column label="任务" min-width="190"><template #default="{ row }"><strong>{{ row.name }}</strong><small class="agent-batch-cell-note">#{{ row.id }} · {{ formatDateTime(row.createdAt, "—") }}</small></template></el-table-column>
      <el-table-column label="配置快照" min-width="180"><template #default="{ row }"><span>{{ row.modelName }}</span><small class="agent-batch-cell-note">{{ row.knowledgeNames.join('、') }}</small></template></el-table-column>
      <el-table-column label="进度" min-width="190"><template #default="{ row }"><el-progress :percentage="row.progress" :status="row.status === 'completed' ? 'success' : undefined" /><small class="agent-batch-cell-note">{{ row.processedCount }}/{{ row.totalCount }} · 成功 {{ row.successCount }} · 失败 {{ row.failedCount }}</small></template></el-table-column>
      <el-table-column label="执行方式" width="118"><template #default="{ row }"><el-tag type="info">{{ executionLabel(row) }}</el-tag></template></el-table-column>
--- a/ai_knowledge_base_v2/apps/admin-web/src/components/AgentManagementView.vue
+++ b/ai_knowledge_base_v2/apps/admin-web/src/components/AgentManagementView.vue
@@ -9,6 +9,7 @@ import AgentBatchTestPanel from "./AgentBatchTestPanel.vue";
 import AgentResponseDepthControl from "./AgentResponseDepthControl.vue";
 import AdminPagination from "./AdminPagination.vue";
 import StreamingMarkdownMessage from "./StreamingMarkdownMessage.vue";
+import { formatDateTime } from "../utils/dateTime";

 const props = withDefaults(defineProps<{ previewKnowledgeId?: number | null; canBatch?: boolean }>(), { canBatch: false });
 const emit = defineEmits<{ consumedPreview: [] }>();
@@ -479,11 +480,6 @@ function changeTypeTag(value?: string) {
  return "info";
 }

-function formatDate(value?: string | null) {
-  if (!value) return "尚未保存";
-  return new Date(value).toLocaleString("zh-CN", { hour12: false });
-}
-
 function errorMessage(error: unknown, fallback: string) {
  return error instanceof Error ? error.message : fallback;
 }
@@ -497,7 +493,7 @@ function errorMessage(error: unknown, fallback: string) {
    </div>
    <div class="agent-current-summary">
      <el-tag type="success">当前版本 {{ prompt?.id ? `#${prompt.id}` : "系统默认" }}</el-tag>
-      <span>{{ prompt?.updatedByName || "系统默认" }} · {{ formatDate(prompt?.updatedAt) }}</span>
+      <span>{{ prompt?.updatedByName || "系统默认" }} · {{ formatDateTime(prompt?.updatedAt, "尚未保存") }}</span>
    </div>
  </div>

@@ -697,7 +693,7 @@ function errorMessage(error: unknown, fallback: string) {
                <strong>版本 #{{ item.id }}</strong>
                <el-tag v-if="item.isCurrent" type="success" size="small">当前</el-tag>
                <el-tag :type="changeTypeTag(item.changeType)" size="small">{{ changeTypeLabel(item.changeType) }}</el-tag>
-                <span>{{ item.updatedByName }} · {{ formatDate(item.updatedAt) }}</span>
+                <span>{{ item.updatedByName }} · {{ formatDateTime(item.updatedAt, "尚未保存") }}</span>
              </div>
              <p>{{ item.preview || "空内容" }}</p>
              <div class="prompt-history-foot">
@@ -759,7 +755,7 @@ function errorMessage(error: unknown, fallback: string) {
  <el-dialog v-model="historyDetailOpen" width="min(820px, 92vw)" title="主提示词历史版本" destroy-on-close>
    <div v-loading="historyDetailLoading" class="prompt-history-detail">
      <template v-if="selectedHistory">
-        <div class="prompt-history-detail-meta"><el-tag :type="changeTypeTag(selectedHistory.changeType)">{{ changeTypeLabel(selectedHistory.changeType) }}</el-tag><strong>版本 #{{ selectedHistory.id }}</strong><span>{{ selectedHistory.updatedByName }} · {{ formatDate(selectedHistory.updatedAt) }} · {{ selectedHistory.charCount }} 字符</span></div>
+        <div class="prompt-history-detail-meta"><el-tag :type="changeTypeTag(selectedHistory.changeType)">{{ changeTypeLabel(selectedHistory.changeType) }}</el-tag><strong>版本 #{{ selectedHistory.id }}</strong><span>{{ selectedHistory.updatedByName }} · {{ formatDateTime(selectedHistory.updatedAt, "尚未保存") }} · {{ selectedHistory.charCount }} 字符</span></div>
        <pre>{{ selectedHistory.promptContent }}</pre>
      </template>
    </div>
--- a/ai_knowledge_base_v2/apps/admin-web/src/components/AiLogDetailDrawer.vue
+++ b/ai_knowledge_base_v2/apps/admin-web/src/components/AiLogDetailDrawer.vue
@@ -3,6 +3,7 @@ import { ElMessage } from "element-plus";
 import { ref, watch } from "vue";
 import { api } from "../services/api";
 import type { AiLogRecord } from "../types/api";
+import { formatDateTime } from "../utils/dateTime";

 const props = defineProps<{ modelValue: boolean; logId: number | null }>();
 const emit = defineEmits<{ "update:modelValue": [value: boolean] }>();
@@ -77,7 +78,7 @@ function formatMoney(value?: number | null, currency = "CNY") {
          ><span>知识命中：{{ detail.knowledgeHit ? "是" : "否" }}</span
          ><span>路由原因：{{ detail.routeReason || "-" }}</span
          ><span>耗时：{{ detail.costMs || "-" }}ms</span
-          ><span>时间：{{ detail.createdAt }}</span>
+          ><span>时间：{{ formatDateTime(detail.createdAt) }}</span>
        </section>
        <p v-if="detail.errorMessage" class="error-text">
          {{ detail.errorMessage }}
--- a/ai_knowledge_base_v2/apps/admin-web/src/components/AttentionManagementView.vue
+++ b/ai_knowledge_base_v2/apps/admin-web/src/components/AttentionManagementView.vue
@@ -6,19 +6,28 @@ import type { AttentionItem } from "../types/api";
 import AdminPagination from "./AdminPagination.vue";
 import AttentionRuleConfigPanel from "./AttentionRuleConfigPanel.vue";
 import ChatDetailDrawer from "./ChatDetailDrawer.vue";
+import { formatDateTime, toUtcIsoFromBusinessDate } from "../utils/dateTime";

 defineProps<{ canConfig: boolean; canPreview: boolean }>();

 const loading = ref(false);
 const records = ref<AttentionItem[]>([]);
 const pager = reactive({ page: 1, pageSize: 20, total: 0 });
+const filters = reactive({ priority: "", dateFrom: "", dateTo: "" });
 const chatDetailOpen = ref(false);
 const sessionId = ref<number | null>(null);
+const focusMessageId = ref<number | null>(null);
 onMounted(() => loadRecords());
 async function loadRecords(page = 1, pageSize = pager.pageSize) {
  loading.value = true;
  try {
-    const result = await api.attentionList({ page, pageSize });
+    const result = await api.attentionList({
+      priority: filters.priority || undefined,
+      dateFrom: toUtcIsoFromBusinessDate(filters.dateFrom, "start"),
+      dateTo: toUtcIsoFromBusinessDate(filters.dateTo, "end"),
+      page,
+      pageSize,
+    });
    records.value = result.items;
    Object.assign(pager, {
      page: result.page,
@@ -29,6 +38,17 @@ async function loadRecords(page = 1, pageSize = pager.pageSize) {
    loading.value = false;
  }
 }
+function applyFilters() {
+  if (filters.dateFrom && filters.dateTo && filters.dateFrom > filters.dateTo) {
+    ElMessage.warning("开始日期不能晚于结束日期");
+    return;
+  }
+  void loadRecords(1, pager.pageSize);
+}
+function resetFilters() {
+  Object.assign(filters, { priority: "", dateFrom: "", dateTo: "" });
+  void loadRecords(1, pager.pageSize);
+}
 async function updateStatus(row: AttentionItem, status: string) {
  await api.updateAttention(row.id, status);
  ElMessage.success("人工关注状态已更新");
@@ -52,8 +72,9 @@ async function deleteRecord(row: AttentionItem) {
  ElMessage.success("人工关注记录已删除");
  await loadRecords(pager.page, pager.pageSize);
 }
-function openChat(id: number) {
-  sessionId.value = id;
+function openChat(row: AttentionItem) {
+  sessionId.value = row.sessionId;
+  focusMessageId.value = row.messageId;
  chatDetailOpen.value = true;
 }
 function priorityLabel(priority: string) {
@@ -73,6 +94,22 @@ function priorityLabel(priority: string) {
    </div>
    <el-tabs class="attention-tabs">
      <el-tab-pane label="关注记录">
+    <section class="record-filter attention-toolbar" aria-label="人工关注筛选">
+      <el-select v-model="filters.priority" placeholder="全部优先级" clearable aria-label="优先级">
+        <el-option label="紧急" value="urgent" />
+        <el-option label="重要" value="important" />
+        <el-option label="普通" value="normal" />
+      </el-select>
+      <div class="record-date-range" aria-label="触发时间范围">
+        <label class="record-date-field"><span>开始日期</span><input v-model="filters.dateFrom" type="date" aria-label="人工关注开始日期" /></label>
+        <span class="record-date-sep">至</span>
+        <label class="record-date-field"><span>结束日期</span><input v-model="filters.dateTo" type="date" aria-label="人工关注结束日期" /></label>
+      </div>
+      <div class="record-filter-actions">
+        <el-button type="primary" @click="applyFilters">查询</el-button>
+        <el-button @click="resetFilters">重置</el-button>
+      </div>
+    </section>
    <el-table :data="records" stripe
      ><el-table-column label="优先级" width="100"
        ><template #default="{ row }"
@@ -116,13 +153,18 @@ function priorityLabel(priority: string) {
              value="resolved" /><el-option
              label="无需处理"
              value="ignored" /></el-select></template></el-table-column
-      ><el-table-column
-        prop="createdAt"
-        label="创建时间"
-        width="180"
-      /><el-table-column label="操作" width="130" fixed="right"
+      ><el-table-column label="触发时间" width="180"
+        ><template #default="{ row }">{{ formatDateTime(row.createdAt) }}</template
+      ></el-table-column><el-table-column label="操作" width="130" fixed="right"
        ><template #default="{ row }"
-          ><el-button link type="primary" @click="openChat(row.sessionId)"
+          ><el-tooltip
+            v-if="row.targetAvailable === false"
+            content="原会话或触发消息已删除"
+            placement="top"
+          >
+            <span><el-button link disabled>原会话</el-button></span>
+          </el-tooltip>
+          <el-button v-else link type="primary" @click="openChat(row)"
            >原会话</el-button
          ><el-button link type="danger" @click="deleteRecord(row)"
            >删除</el-button
@@ -134,7 +176,11 @@ function priorityLabel(priority: string) {
      :page-size="pager.pageSize"
      :total="pager.total"
      @change="loadRecords"
-    /><ChatDetailDrawer v-model="chatDetailOpen" :session-id="sessionId" />
+    /><ChatDetailDrawer
+      v-model="chatDetailOpen"
+      :session-id="sessionId"
+      :focus-message-id="focusMessageId"
+    />
      </el-tab-pane>
      <el-tab-pane v-if="canConfig || canPreview" label="筛选规则与预览" lazy>
        <AttentionRuleConfigPanel :can-config="canConfig" :can-preview="canPreview" />
@@ -145,4 +191,18 @@ function priorityLabel(priority: string) {

 <style scoped>
 .attention-tabs { margin-top: 14px; }
+.attention-toolbar {
+  align-items: center;
+  margin-bottom: 16px;
+  padding: 14px 16px;
+  border: 1px solid #e7ebf0;
+  border-radius: 12px;
+  background: #fafbfc;
+}
+@media (max-width: 900px) {
+  .attention-toolbar { align-items: stretch; }
+  .attention-toolbar .record-date-range { width: 100%; }
+  .attention-toolbar .record-date-field { flex: 1; width: auto; }
+  .attention-toolbar .record-filter-actions { width: 100%; }
+}
 </style>
--- a/ai_knowledge_base_v2/apps/admin-web/src/components/AttentionRuleConfigPanel.vue
+++ b/ai_knowledge_base_v2/apps/admin-web/src/components/AttentionRuleConfigPanel.vue
@@ -5,6 +5,7 @@ import { computed, onMounted, reactive, ref } from "vue";
 import { api } from "../services/api";
 import type { AttentionConfig, AttentionPreviewMessage, AttentionPreviewResult } from "../types/api";
 import AdminPagination from "./AdminPagination.vue";
+import { formatDateTime } from "../utils/dateTime";

 const props = defineProps<{ canConfig: boolean; canPreview: boolean }>();

@@ -182,7 +183,7 @@ function sourceLabel(value: string) {
        <el-table-column prop="userName" label="用户" width="120" />
        <el-table-column prop="sessionTitle" label="会话" min-width="180" show-overflow-tooltip />
        <el-table-column label="知识缺失" width="100"><template #default="{ row }"><el-tag :type="row.knowledgeMissing ? 'warning' : 'info'">{{ row.knowledgeMissing ? "是" : "否" }}</el-tag></template></el-table-column>
-        <el-table-column prop="createdAt" label="提问时间" width="180" />
+        <el-table-column label="提问时间" width="180"><template #default="{ row }">{{ formatDateTime(row.createdAt) }}</template></el-table-column>
      </el-table>
      <AdminPagination :page="pager.page" :page-size="pager.pageSize" :total="pager.total" @change="loadPreviewMessages" />
    </article>
--- a/ai_knowledge_base_v2/apps/admin-web/src/components/ChatDetailDrawer.vue
+++ b/ai_knowledge_base_v2/apps/admin-web/src/components/ChatDetailDrawer.vue
@@ -5,17 +5,24 @@ import { nextTick, reactive, ref, watch } from "vue";
 import { api } from "../services/api";
 import type { ChatDetail } from "../types/api";
 import AdminPagination from "./AdminPagination.vue";
+import { formatDateTime } from "../utils/dateTime";

-const props = defineProps<{ modelValue: boolean; sessionId: number | null }>();
+const props = defineProps<{
+  modelValue: boolean;
+  sessionId: number | null;
+  focusMessageId?: number | null;
+  canExport?: boolean;
+}>();
 const emit = defineEmits<{ "update:modelValue": [value: boolean] }>();
 const detail = ref<ChatDetail | null>(null);
 const loading = ref(false);
 const messagesLoading = ref(false);
+const exporting = ref(false);
 const bodyRef = ref<HTMLElement | null>(null);
 const pager = reactive({ page: 1, pageSize: 20, total: 0 });

 watch(
-  () => [props.modelValue, props.sessionId] as const,
+  () => [props.modelValue, props.sessionId, props.focusMessageId] as const,
  async ([open, sessionId]) => {
    if (!open || !sessionId) return;
    detail.value = null;
@@ -30,6 +37,7 @@ async function loadDetail(sessionId: number, page: number, pageSize: number) {
    detail.value = await api.chatDetail(sessionId, {
      messagePage: page,
      messagePageSize: pageSize,
+      focusMessageId: props.focusMessageId || undefined,
    });
    const messagePage = detail.value.messagesPage;
    Object.assign(pager, {
@@ -37,6 +45,7 @@ async function loadDetail(sessionId: number, page: number, pageSize: number) {
      pageSize: messagePage?.pageSize ?? pageSize,
      total: messagePage?.total ?? detail.value.messages.length,
    });
+    await scrollToFocusedMessage();
  } catch (error) {
    ElMessage.error(
      error instanceof Error ? error.message : "聊天详情加载失败",
@@ -46,6 +55,15 @@ async function loadDetail(sessionId: number, page: number, pageSize: number) {
  }
 }

+async function scrollToFocusedMessage() {
+  if (!props.focusMessageId) return;
+  await nextTick();
+  const target = bodyRef.value?.querySelector<HTMLElement>(
+    `[data-message-id="${props.focusMessageId}"]`,
+  );
+  target?.scrollIntoView({ behavior: "smooth", block: "center" });
+}
+
 async function changeMessagePage(page: number, pageSize: number) {
  if (!props.sessionId || !detail.value) return;
  messagesLoading.value = true;
@@ -71,6 +89,19 @@ async function changeMessagePage(page: number, pageSize: number) {
    messagesLoading.value = false;
  }
 }
+
+async function exportConversation() {
+  if (!props.sessionId) return;
+  exporting.value = true;
+  try {
+    await api.exportChatDetail(props.sessionId);
+    ElMessage.success("当前完整对话已导出");
+  } catch (error) {
+    ElMessage.error(error instanceof Error ? error.message : "完整对话导出失败");
+  } finally {
+    exporting.value = false;
+  }
+}
 </script>

 <template>
@@ -82,6 +113,9 @@ async function changeMessagePage(page: number, pageSize: number) {
  >
    <div ref="bodyRef" v-loading="loading" class="chat-detail-body">
      <template v-if="detail">
+        <div v-if="canExport" class="chat-detail-actions">
+          <el-button type="primary" plain :loading="exporting" @click="exportConversation">导出完整对话</el-button>
+        </div>
        <section class="chat-summary">
          <div>
            <span>会话ID</span><strong>{{ detail.session.id }}</strong>
@@ -115,8 +149,8 @@ async function changeMessagePage(page: number, pageSize: number) {
                ><span>消息数：{{ topic.messageCount }}</span
                ><span
                  >Token：{{ topic.tokenInput }}/{{ topic.tokenOutput }}</span
-                ><span>开始：{{ topic.startedAt }}</span
-                ><span>结束：{{ topic.endedAt || "-" }}</span>
+                ><span>开始：{{ formatDateTime(topic.startedAt) }}</span
+                ><span>结束：{{ formatDateTime(topic.endedAt) }}</span>
              </div>
              <template v-if="topic.summary">
                <pre>{{ topic.summary.summary }}</pre>
@@ -151,8 +185,8 @@ async function changeMessagePage(page: number, pageSize: number) {
            :title="`#${card.id} / 主题 #${card.topicSessionId} / ${card.copied ? '用户已复制' : '未复制'}`"
            ><section class="topic-summary-card">
              <div class="topic-summary-meta">
-                <span>生成：{{ card.createdAt }}</span
-                ><span>复制：{{ card.copiedAt || "-" }}</span
+                <span>生成：{{ formatDateTime(card.createdAt) }}</span
+                ><span>复制：{{ formatDateTime(card.copiedAt) }}</span
                ><span>来源：{{ card.source }}</span>
              </div>
              <pre>{{ card.content }}</pre>
@@ -176,8 +210,8 @@ async function changeMessagePage(page: number, pageSize: number) {
            :title="`#${draft.id} / 主题 #${draft.topicSessionId} / ${draft.copied ? '用户已复制' : '未复制'}`"
            ><section class="topic-summary-card">
              <div class="topic-summary-meta">
-                <span>生成：{{ draft.createdAt }}</span
-                ><span>复制：{{ draft.copiedAt || "-" }}</span
+                <span>生成：{{ formatDateTime(draft.createdAt) }}</span
+                ><span>复制：{{ formatDateTime(draft.copiedAt) }}</span
                ><span>来源：{{ draft.source }}</span>
              </div>
              <pre>{{ draft.content }}</pre>
@@ -202,13 +236,22 @@ async function changeMessagePage(page: number, pageSize: number) {
            v-for="message in detail.messages"
            :key="message.id"
            class="conversation-message"
-            :class="message.role"
+            :class="[
+              message.role,
+              { 'focus-message': message.id === focusMessageId },
+            ]"
+            :data-message-id="message.id"
          >
            <div class="message-meta">
              <strong>{{
                message.role === "user" ? "用户" : "大本营答疑助手"
              }}</strong
-              ><span>{{ message.createdAt }}</span>
+              ><el-tag
+                v-if="message.id === focusMessageId"
+                type="warning"
+                effect="light"
+                >触发人工关注的消息</el-tag
+              ><span>{{ formatDateTime(message.createdAt) }}</span>
            </div>
            <pre>{{ message.content }}</pre>
            <div class="message-extra">
@@ -242,7 +285,7 @@ async function changeMessagePage(page: number, pageSize: number) {
              ><span>命中数：{{ log.retrieveCount }}</span
              ><span>Token：{{ log.totalToken || "-" }}</span
              ><span>耗时：{{ log.costMs || "-" }}ms</span
-              ><span>时间：{{ log.createdAt }}</span>
+              ><span>时间：{{ formatDateTime(log.createdAt) }}</span>
            </div>
            <section
              v-if="log.retrievedChunks?.length"
@@ -291,3 +334,26 @@ async function changeMessagePage(page: number, pageSize: number) {
    </div>
  </el-drawer>
 </template>
+
+<style scoped>
+.chat-detail-actions {
+  display: flex;
+  justify-content: flex-end;
+  margin-bottom: 14px;
+}
+
+.conversation-message.focus-message {
+  border: 2px solid #e6a23c;
+  background: #fffaf0;
+  box-shadow: 0 0 0 4px rgb(230 162 60 / 10%);
+}
+
+.conversation-message.focus-message .message-meta {
+  align-items: center;
+  gap: 10px;
+}
+
+.conversation-message.focus-message .message-meta span:last-child {
+  margin-left: auto;
+}
+</style>
--- a/ai_knowledge_base_v2/apps/admin-web/src/components/ContentGenerationConfigView.vue
+++ b/ai_knowledge_base_v2/apps/admin-web/src/components/ContentGenerationConfigView.vue
@@ -12,6 +12,7 @@ import type {
 } from "../types/api";
 import AdminPagination from "./AdminPagination.vue";
 import ContentGenerationVariableEditor from "./ContentGenerationVariableEditor.vue";
+import { formatDateTime } from "../utils/dateTime";

 const activeType = ref<ContentGenerationType>("help_card");
 const loading = ref(false);
@@ -259,11 +260,6 @@ async function restoreHistory(id: number) {
  }
 }

-function formatTime(value?: string | null) {
-  if (!value) return "系统默认";
-  return new Date(value).toLocaleString("zh-CN", { hour12: false });
-}
-
 function changeTypeLabel(value: string) {
  return { save: "保存", reset: "恢复默认", restore: "历史回滚", default: "系统默认" }[value] || value;
 }
@@ -374,7 +370,7 @@ function changeTypeLabel(value: string) {

    <section class="generation-history generation-panel">
      <header>
-        <div><h3>版本记录</h3><p>当前配置：{{ current?.updatedByName }} · {{ formatTime(current?.updatedAt) }}</p></div>
+        <div><h3>版本记录</h3><p>当前配置：{{ current?.updatedByName }} · {{ formatDateTime(current?.updatedAt, "系统默认") }}</p></div>
        <el-tag v-if="current" type="success">{{ changeTypeLabel(current.changeType) }}</el-tag>
      </header>
      <el-empty v-if="!history.length" description="尚未保存过版本，当前使用系统默认配置" :image-size="72" />
@@ -383,7 +379,7 @@ function changeTypeLabel(value: string) {
          <div>
            <strong>版本 #{{ item.id }} <el-tag v-if="item.isCurrent" size="small" type="success">当前</el-tag></strong>
            <p>{{ item.preview }}</p>
-            <small>{{ changeTypeLabel(item.changeType) }} · {{ item.updatedByName }} · {{ formatTime(item.updatedAt) }}</small>
+            <small>{{ changeTypeLabel(item.changeType) }} · {{ item.updatedByName }} · {{ formatDateTime(item.updatedAt, "系统默认") }}</small>
          </div>
          <el-button @click="openHistory(item)">查看</el-button>
        </article>
@@ -404,7 +400,7 @@ function changeTypeLabel(value: string) {
            <div><dt>版本</dt><dd>#{{ selectedHistory.id }}</dd></div>
            <div><dt>操作</dt><dd>{{ changeTypeLabel(selectedHistory.changeType) }}</dd></div>
            <div><dt>操作人</dt><dd>{{ selectedHistory.updatedByName }}</dd></div>
-            <div><dt>时间</dt><dd>{{ formatTime(selectedHistory.updatedAt) }}</dd></div>
+            <div><dt>时间</dt><dd>{{ formatDateTime(selectedHistory.updatedAt, "系统默认") }}</dd></div>
          </dl>
          <h4>变量定义</h4>
          <div class="history-variables">
--- a/ai_knowledge_base_v2/apps/admin-web/src/components/DashboardView.vue
+++ b/ai_knowledge_base_v2/apps/admin-web/src/components/DashboardView.vue
@@ -8,6 +8,7 @@ import { nextTick, onBeforeUnmount, onMounted, reactive, ref } from "vue";

 import { api } from "../services/api";
 import type { DashboardStats, PeakTrafficResult, TrafficGrain } from "../types/api";
+import { formatDateTime } from "../utils/dateTime";

 use([LineChart, GridComponent, TooltipComponent, LegendComponent, DataZoomComponent, MarkPointComponent, CanvasRenderer]);

@@ -160,7 +161,7 @@ function modelSceneLabel(scene: string) {
    <section class="dashboard-panel" v-loading="storageLoading">
      <div class="panel-heading"><div><span class="section-kicker">基础设施</span><h3>项目存储占用</h3><p>数据库、Redis 与附件分别统计，无法取得时明确标记。</p></div><el-button :loading="storageLoading" @click="refreshStorage">手动刷新</el-button></div>
      <div class="storage-grid"><div><span>项目总量</span><strong>{{ formatBytes(storageStats?.totalBytes) }}</strong></div><div><span>数据库</span><strong>{{ formatBytes(storageStats?.detail?.database?.bytes) }}</strong></div><div><span>Redis</span><strong>{{ formatBytes(storageStats?.detail?.redis?.bytes) }}</strong></div><div><span>附件/文件</span><strong>{{ formatBytes(storageStats?.detail?.files?.bytes) }}</strong></div><div><span>近7天增长</span><strong>{{ formatBytes(storageStats?.growth7DaysBytes) }}</strong></div><div><span>近30天增长</span><strong>{{ formatBytes(storageStats?.growth30DaysBytes) }}</strong></div></div>
-      <small class="storage-updated">最后统计：{{ storageStats?.createdAt || "尚未统计" }}</small>
+      <small class="storage-updated">最后统计：{{ formatDateTime(storageStats?.createdAt, "尚未统计") }}</small>
    </section>
  </section>
 </template>
--- a/ai_knowledge_base_v2/apps/admin-web/src/components/FeedbackManagementView.vue
+++ b/ai_knowledge_base_v2/apps/admin-web/src/components/FeedbackManagementView.vue
@@ -5,6 +5,7 @@ import { onMounted, ref } from "vue";
 import { api } from "../services/api";
 import type { FeedbackDetail, FeedbackItem } from "../types/api";
 import AdminPagination from "./AdminPagination.vue";
+import { formatDateTime } from "../utils/dateTime";

 defineProps<{ canDelete: boolean; canDetail: boolean; canExport: boolean }>();

@@ -119,13 +120,13 @@ onMounted(load);
      <el-table-column prop="userName" label="用户" width="130" />
      <el-table-column prop="content" label="反馈内容" min-width="240" show-overflow-tooltip />
      <el-table-column prop="messageContent" label="反馈的 AI 回答" min-width="280" show-overflow-tooltip />
-      <el-table-column prop="createdAt" label="提交时间" width="180" />
+      <el-table-column label="提交时间" width="180"><template #default="{ row }">{{ formatDateTime(row.createdAt) }}</template></el-table-column>
      <el-table-column label="操作" width="150" fixed="right"><template #default="{ row }"><el-button v-if="canDetail" link type="primary" @click="open(row)">查看</el-button><el-button v-if="canDelete" link type="danger" @click="remove(row)">删除</el-button></template></el-table-column>
    </el-table>
    <AdminPagination v-if="total" :page="page" :page-size="pageSize" :total="total" @change="changePage" />
    <el-drawer :model-value="Boolean(detail)" title="反馈详情" size="620px" @close="detail = null">
      <template v-if="detail">
-        <section class="feedback-summary"><span>用户反馈</span><strong>{{ detail.content }}</strong><small>{{ detail.userName }} · {{ detail.createdAt }}</small></section>
+        <section class="feedback-summary"><span>用户反馈</span><strong>{{ detail.content }}</strong><small>{{ detail.userName }} · {{ formatDateTime(detail.createdAt) }}</small></section>
        <h3>当时对话记录</h3>
        <div class="feedback-history"><article v-for="message in detail.messages" :key="message.id" :class="[message.role, { target: message.isTarget }]">
          <div><b>{{ message.role === 'user' ? '用户' : 'AI' }}</b><el-tag v-if="message.isTarget" type="warning">用户反馈的这条回答</el-tag></div><p>{{ message.content }}</p>
--- a/ai_knowledge_base_v2/apps/admin-web/src/components/KnowledgeManagementView.vue
+++ b/ai_knowledge_base_v2/apps/admin-web/src/components/KnowledgeManagementView.vue
@@ -3,6 +3,7 @@ import { ElMessage, ElMessageBox } from "element-plus";
 import { onMounted, reactive, ref } from "vue";

 import { api } from "../services/api";
+import { formatDateTime } from "../utils/dateTime";
 import KnowledgeContentPreview from "./KnowledgeContentPreview.vue";
 import TableRowActions from "./TableRowActions.vue";
 import AdminPagination from "./AdminPagination.vue";
@@ -545,7 +546,7 @@ async function confirmAction(
    <el-table-column label="类型" width="140"><template #default="{ row }">{{ typeLabel(row.knowledgeType) }}</template></el-table-column>
    <el-table-column label="当前版本" width="130"><template #default="{ row }"><span>{{ row.currentVersionId ? `#${row.currentVersionId}` : '尚未同步' }}</span></template></el-table-column>
    <el-table-column label="状态" width="210"><template #default="{ row }"><div class="knowledge-status-cell"><el-switch v-model="row.status" :active-value="1" :inactive-value="0" active-text="开放" inactive-text="关闭" inline-prompt :loading="operatingId === row.id" :disabled="row.lifecycleStatus === 'archived'" :before-change="() => toggleOpen(row)" /><el-tag :type="statusType(row.sourceStatus)">{{ row.sourceStatus === 'normal' ? '源正常' : '源异常' }}</el-tag></div></template></el-table-column>
-    <el-table-column prop="lastSyncedAt" label="最近同步" width="180" />
+    <el-table-column label="最近同步" width="180"><template #default="{ row }">{{ formatDateTime(row.lastSyncedAt) }}</template></el-table-column>
    <el-table-column label="操作" width="220" fixed="right"><template #default="{ row }"><TableRowActions><el-button link type="primary" @click="openDetail(row)">详情</el-button><el-button link type="primary" :disabled="row.lifecycleStatus === 'archived'" :loading="operatingId === row.id" @click="sync(row)">同步最新版</el-button><el-dropdown trigger="click" :teleported="true" @command="handleMore($event, row)"><el-button link type="primary">更多</el-button><template #dropdown><el-dropdown-menu><el-dropdown-item command="detail">查看详情</el-dropdown-item><el-dropdown-item command="preview">进入 Agent 预览</el-dropdown-item><el-dropdown-item v-if="row.lifecycleStatus === 'active'" command="archive" divided>归档</el-dropdown-item><el-dropdown-item v-else command="restore" divided>恢复</el-dropdown-item><el-dropdown-item command="delete" divided>永久删除</el-dropdown-item></el-dropdown-menu></template></el-dropdown></TableRowActions></template></el-table-column>
  </el-table>
  <AdminPagination :page="pager.page" :page-size="pager.pageSize" :total="pager.total" @change="load" />
--- a/ai_knowledge_base_v2/apps/admin-web/src/components/RecordAuditView.vue
+++ b/ai_knowledge_base_v2/apps/admin-web/src/components/RecordAuditView.vue
@@ -11,6 +11,9 @@ import type {
 import AdminPagination from "./AdminPagination.vue";
 import AiLogDetailDrawer from "./AiLogDetailDrawer.vue";
 import ChatDetailDrawer from "./ChatDetailDrawer.vue";
+import { formatDateTime, toUtcIsoFromBusinessDateTime } from "../utils/dateTime";
+
+defineProps<{ canExport: boolean }>();

 type RecordTab = "chats" | "questionInsights" | "aiLogs" | "operationLogs";
 const loading = ref(false);
@@ -115,8 +118,8 @@ async function loadInsights(
  pageSize = pagers.questionInsights.pageSize,
 ) {
  insights.value = await api.questionInsights({
-    dateFrom: formatDateTime(insightFilters.dateFrom, "start"),
-    dateTo: formatDateTime(insightFilters.dateTo, "end"),
+    dateFrom: toUtcIsoFromBusinessDateTime(insightFilters.dateFrom),
+    dateTo: toUtcIsoFromBusinessDateTime(insightFilters.dateTo),
    minCount: insightFilters.minCount,
    maxMessages: insightFilters.maxMessages,
    page,
@@ -149,8 +152,8 @@ async function refreshInsights() {
  loading.value = true;
  try {
    const result = await api.refreshQuestionInsights({
-      dateFrom: formatDateTime(insightFilters.dateFrom, "start"),
-      dateTo: formatDateTime(insightFilters.dateTo, "end"),
+      dateFrom: toUtcIsoFromBusinessDateTime(insightFilters.dateFrom),
+      dateTo: toUtcIsoFromBusinessDateTime(insightFilters.dateTo),
      maxMessages: insightFilters.maxMessages,
    });
    await loadInsights(1);
@@ -177,9 +180,9 @@ async function resetInsightFilters() {
  await refreshInsights();
 }
 async function exportInsights() {
-  const dateFrom = formatDateTime(insightFilters.dateFrom, "start");
-  const dateTo = formatDateTime(insightFilters.dateTo, "end");
-  if (dateFrom && dateTo && new Date(dateFrom.replace(" ", "T")) > new Date(dateTo.replace(" ", "T"))) {
+  const dateFrom = toUtcIsoFromBusinessDateTime(insightFilters.dateFrom);
+  const dateTo = toUtcIsoFromBusinessDateTime(insightFilters.dateTo);
+  if (dateFrom && dateTo && dateFrom > dateTo) {
    return ElMessage.warning("开始时间不能晚于结束时间");
  }
  insightExporting.value = true;
@@ -217,17 +220,10 @@ function buildChatQuery() {
    status: chatFilters.status,
    sourceType: chatFilters.sourceType,
    sourceClientId: chatFilters.sourceClientId,
-    dateFrom: formatDateTime(chatFilters.dateFrom, "start"),
-    dateTo: formatDateTime(chatFilters.dateTo, "end"),
+    dateFrom: toUtcIsoFromBusinessDateTime(chatFilters.dateFrom),
+    dateTo: toUtcIsoFromBusinessDateTime(chatFilters.dateTo),
  };
 }
-function formatDateTime(value: string, boundary: "start" | "end") {
-  if (!value) return "";
-  const [date, time = ""] = value.trim().replace("T", " ").split(" ");
-  if (!date) return "";
-  const [hour = "00", minute = "00", second] = time.split(":");
-  return `${date} ${hour.padStart(2, "0")}:${minute.padStart(2, "0")}:${(second ?? (boundary === "end" ? "59" : "00")).padStart(2, "0")}`;
-}
 function formatMoney(value?: number | null, currency = "CNY") {
  return typeof value === "number"
    ? `${currency || "CNY"} ${value.toFixed(6)}`
@@ -290,7 +286,7 @@ function formatMoney(value?: number | null, currency = "CNY") {
          <div class="record-filter-actions">
            <el-button type="primary" @click="searchChats">搜索</el-button
            ><el-button @click="resetChatFilters">重置</el-button
-            ><el-button @click="api.exportChats(buildChatQuery())"
+            ><el-button v-if="canExport" @click="api.exportChats(buildChatQuery())"
              >导出</el-button
            >
          </div>
@@ -322,11 +318,9 @@ function formatMoney(value?: number | null, currency = "CNY") {
            prop="messageCount"
            label="消息数"
            width="90"
-          /><el-table-column
-            prop="lastMessageAt"
-            label="最后消息"
-            width="180"
-          /><el-table-column label="操作" width="100" fixed="right"
+          /><el-table-column label="最后消息" width="180"
+            ><template #default="{ row }">{{ formatDateTime(row.lastMessageAt) }}</template
+          ></el-table-column><el-table-column label="操作" width="100" fixed="right"
            ><template #default="{ row }"
              ><el-button size="small" @click="openChat(row.id)"
                >详情</el-button
@@ -382,7 +376,7 @@ function formatMoney(value?: number | null, currency = "CNY") {
              @click="refreshInsights"
              >刷新并统计</el-button
            ><el-button @click="resetInsightFilters">重置</el-button>
-            <el-button :loading="insightExporting" @click="exportInsights">导出洞察</el-button>
+            <el-button v-if="canExport" :loading="insightExporting" @click="exportInsights">导出洞察</el-button>
          </div>
        </div>
        <p class="question-insight-help">
@@ -475,7 +469,7 @@ function formatMoney(value?: number | null, currency = "CNY") {
                        sample.userPhone ||
                        `用户 #${sample.userId}`
                      }}</strong
-                      ><span>{{ sample.createdAt }}</span>
+                      ><span>{{ formatDateTime(sample.createdAt) }}</span>
                    </div>
                    <p>清洗后：{{ sample.cleaned }}</p>
                    <pre>{{ sample.raw }}</pre>
@@ -569,9 +563,9 @@ function formatMoney(value?: number | null, currency = "CNY") {
            prop="action"
            label="动作" /><el-table-column
            prop="result"
-            label="结果" /><el-table-column
-            prop="createdAt"
-            label="时间" /></el-table
+            label="结果" /><el-table-column label="时间" width="180"
+            ><template #default="{ row }">{{ formatDateTime(String(row.createdAt || "")) }}</template
+          ></el-table-column></el-table
        ><AdminPagination
          :page="pagers.operationLogs.page"
          :page-size="pagers.operationLogs.pageSize"
@@ -579,7 +573,7 @@ function formatMoney(value?: number | null, currency = "CNY") {
          @change="(page, size) => changePage('operationLogs', page, size)"
      /></el-tab-pane>
    </el-tabs>
-    <ChatDetailDrawer v-model="chatDetailOpen" :session-id="detailSessionId" />
+    <ChatDetailDrawer v-model="chatDetailOpen" :session-id="detailSessionId" :can-export="canExport" />
    <AiLogDetailDrawer v-model="aiLogDetailOpen" :log-id="aiLogId" />
  </section>
 </template>
--- a/ai_knowledge_base_v2/apps/admin-web/src/components/RetrievalLogView.vue
+++ b/ai_knowledge_base_v2/apps/admin-web/src/components/RetrievalLogView.vue
@@ -4,6 +4,7 @@ import { computed, onMounted, reactive, ref } from "vue";
 import { api } from "../services/api";
 import type { RetrievalLogItem } from "../types/api";
 import AdminPagination from "./AdminPagination.vue";
+import { formatDateTime } from "../utils/dateTime";

 const loading = ref(false);
 const logs = ref<RetrievalLogItem[]>([]);
@@ -102,7 +103,7 @@ async function openDetail(row: RetrievalLogItem) {
          label="180天"
          :value="180" /></el-select
      ><el-button type="primary" @click="saveRetention">保存规则</el-button
-      ><small>最近执行：{{ retentionState?.lastRunAt || "尚未执行" }}</small>
+      ><small>最近执行：{{ formatDateTime(retentionState?.lastRunAt, "尚未执行") }}</small>
    </section>
    <el-table :data="logs" stripe
      ><el-table-column prop="id" label="ID" width="80" /><el-table-column
@@ -136,11 +137,9 @@ async function openDetail(row: RetrievalLogItem) {
        prop="totalCostMs"
        label="总耗时"
        width="100"
-      /><el-table-column
-        prop="createdAt"
-        label="时间"
-        width="180"
-      /><el-table-column label="操作" width="90" fixed="right"
+      /><el-table-column label="时间" width="180"
+        ><template #default="{ row }">{{ formatDateTime(row.createdAt) }}</template
+      ></el-table-column><el-table-column label="操作" width="90" fixed="right"
        ><template #default="{ row }"
          ><el-button link type="primary" @click="openDetail(row)"
            >详情</el-button
--- a/ai_knowledge_base_v2/apps/admin-web/src/components/SsoIntegrationView.vue
+++ b/ai_knowledge_base_v2/apps/admin-web/src/components/SsoIntegrationView.vue
@@ -5,6 +5,7 @@ import { computed, onMounted, reactive, ref } from "vue";
 import { api } from "../services/api";
 import type { EntitlementPlan, SsoAuditItem, SsoClientItem, SsoIdentityItem } from "../types/api";
 import AdminPagination from "./AdminPagination.vue";
+import { formatDateTime } from "../utils/dateTime";

 const loading = ref(false);
 const savingUrl = ref(false);
@@ -266,11 +267,6 @@ async function changeAuditPage(page: number, pageSize: number) {
  await loadAudits();
 }

-function formatTime(value?: string | null) {
-  if (!value) return "-";
-  return new Date(value).toLocaleString("zh-CN", { hour12: false });
-}
-
 function maskPhone(phone: string) {
  return phone.replace(/^(\d{3})\d{4}(\d{4})$/, "$1****$2");
 }
@@ -327,7 +323,7 @@ function showError(error: unknown, fallback: string) {
              <template #default="{ row }">
                <div class="sso-status-cell">
                  <div><el-switch v-model="row.status" :active-value="1" :inactive-value="0" @change="toggleClient(row)" /><span>{{ row.status === 1 ? "已启用" : "已停用" }}</span></div>
-                  <small>最近使用：{{ formatTime(row.lastUsedAt) }}</small>
+                  <small>最近使用：{{ formatDateTime(row.lastUsedAt) }}</small>
                </div>
              </template>
            </el-table-column>
@@ -351,7 +347,7 @@ function showError(error: unknown, fallback: string) {
            <dl>
              <div><dt>账号策略</dt><dd>{{ client.allowAutoRegister ? `自动注册 · ${client.defaultEntitlementPlanName || "未配置权益"}` : "仅已有学员" }}（已绑定 {{ client.identityCount }} 人）</dd></div>
              <div><dt>回跳地址</dt><dd>{{ client.redirectUris.join("、") || "未配置" }}</dd></div>
-              <div><dt>最近使用</dt><dd>{{ formatTime(client.lastUsedAt) }}</dd></div>
+              <div><dt>最近使用</dt><dd>{{ formatDateTime(client.lastUsedAt) }}</dd></div>
            </dl>
            <div class="sso-card-actions"><el-button size="small" @click="openEditDialog(client)">编辑</el-button><el-button size="small" @click="rotateSecret(client)">更新密钥</el-button></div>
          </article>
@@ -374,7 +370,7 @@ function showError(error: unknown, fallback: string) {
          </el-table-column>
          <el-table-column prop="externalUserId" label="外部用户ID" min-width="190" />
          <el-table-column label="最近免登录" width="180">
-            <template #default="{ row }">{{ formatTime(row.lastLoginAt) }}</template>
+            <template #default="{ row }">{{ formatDateTime(row.lastLoginAt) }}</template>
          </el-table-column>
          <el-table-column label="操作" width="120" align="center">
            <template #default="{ row }"><el-button size="small" type="danger" plain @click="unlinkIdentity(row)">解除绑定</el-button></template>
@@ -405,7 +401,7 @@ function showError(error: unknown, fallback: string) {
          </el-table-column>
          <el-table-column prop="errorMessage" label="失败原因" min-width="220" show-overflow-tooltip />
          <el-table-column prop="ip" label="请求IP" width="140" />
-          <el-table-column label="时间" width="180"><template #default="{ row }">{{ formatTime(row.createdAt) }}</template></el-table-column>
+          <el-table-column label="时间" width="180"><template #default="{ row }">{{ formatDateTime(row.createdAt) }}</template></el-table-column>
        </el-table>
        <AdminPagination :page="auditPage" :page-size="auditPageSize" :total="auditTotal" @change="changeAuditPage" />
      </el-tab-pane>
--- a/ai_knowledge_base_v2/apps/admin-web/src/components/UserBehaviorAnalysisView.vue
+++ b/ai_knowledge_base_v2/apps/admin-web/src/components/UserBehaviorAnalysisView.vue
@@ -9,16 +9,23 @@ import type {
  UserBehaviorUserSummary,
 } from "../types/api";
 import AdminPagination from "./AdminPagination.vue";
+import { formatDateTime } from "../utils/dateTime";
+
+defineProps<{ canExport: boolean }>();

 const activeView = ref<"overview" | "users">("overview");
 const overviewLoading = ref(false);
 const usersLoading = ref(false);
+const exporting = ref(false);
 const overview = ref<UserBehaviorOverview | null>(null);
 const users = ref<UserBehaviorUserSummary[]>([]);
 const userTotal = ref(0);
 const userPage = ref(1);
 const userPageSize = ref(20);
 const keyword = ref("");
+type UserSortField = "userName" | "phone" | "eventCount" | "lastEventAt";
+const userSortBy = ref<UserSortField>("lastEventAt");
+const userSortOrder = ref<"asc" | "desc">("desc");
 const timeline = ref<UserBehaviorTimeline | null>(null);
 const timelineLoading = ref(false);
 const timelinePage = ref(1);
@@ -56,6 +63,8 @@ async function loadUsers() {
      keyword: keyword.value.trim() || undefined,
      page: userPage.value,
      pageSize: userPageSize.value,
+      sortBy: userSortBy.value,
+      sortOrder: userSortOrder.value,
    });
    users.value = result.items;
    userTotal.value = result.total;
@@ -67,15 +76,29 @@ async function loadUsers() {
 }

 function applyDateRange() {
-  if (!filters.start || !filters.end) return ElMessage.warning("请选择完整时间范围");
-  if (filters.start > filters.end) return ElMessage.warning("开始日期不能晚于结束日期");
-  const span = (new Date(filters.end).getTime() - new Date(filters.start).getTime()) / 86_400_000;
-  if (span > 30) return ElMessage.warning("行为数据最多查询31天，请缩小时间范围");
+  if (!validateDateRange()) return;
  userPage.value = 1;
  timeline.value = null;
  void loadAll();
 }

+function validateDateRange() {
+  if (!filters.start || !filters.end) {
+    ElMessage.warning("请选择完整时间范围");
+    return false;
+  }
+  if (filters.start > filters.end) {
+    ElMessage.warning("开始日期不能晚于结束日期");
+    return false;
+  }
+  const span = (new Date(filters.end).getTime() - new Date(filters.start).getTime()) / 86_400_000;
+  if (span > 30) {
+    ElMessage.warning("行为数据最多查询 31 天，请缩小时间范围");
+    return false;
+  }
+  return true;
+}
+
 function switchView(view: "overview" | "users") {
  activeView.value = view;
  if (view === "users" && !users.value.length) void loadUsers();
@@ -92,6 +115,32 @@ function changeUserPage(page: number, pageSize: number) {
  void loadUsers();
 }

+function changeUserSort({ prop, order }: { prop: string; order: "ascending" | "descending" | null }) {
+  const supported: UserSortField[] = ["userName", "phone", "eventCount", "lastEventAt"];
+  userSortBy.value = supported.includes(prop as UserSortField) ? prop as UserSortField : "lastEventAt";
+  userSortOrder.value = order === "ascending" ? "asc" : "desc";
+  userPage.value = 1;
+  void loadUsers();
+}
+
+async function exportReport() {
+  if (!validateDateRange() || exporting.value) return;
+  exporting.value = true;
+  try {
+    await api.exportUserBehavior({
+      ...filters,
+      keyword: activeView.value === "users" ? keyword.value.trim() || undefined : undefined,
+      sortBy: userSortBy.value,
+      sortOrder: userSortOrder.value,
+    });
+    ElMessage.success("用户行为分析报表已导出");
+  } catch (error) {
+    ElMessage.error(error instanceof Error ? error.message : "用户行为报表导出失败");
+  } finally {
+    exporting.value = false;
+  }
+}
+
 async function openTimeline(row: UserBehaviorUserSummary, page = 1, pageSize = timelinePageSize.value) {
  timelineLoading.value = true;
  timelinePage.value = page;
@@ -131,10 +180,6 @@ function targetLabel(type?: string | null, id?: number | null) {
  return `${name} #${id}`;
 }

-function formatTime(value: string) {
-  return new Date(value).toLocaleString("zh-CN", { hour12: false });
-}
-
 function formatInputDate(value: Date) {
  const year = value.getFullYear();
  const month = String(value.getMonth() + 1).padStart(2, "0");
@@ -164,6 +209,7 @@ function formatInputDate(value: Date) {
        <i>至</i>
        <label><span>结束日期</span><input v-model="filters.end" type="date" aria-label="行为结束日期" /></label>
        <el-button type="primary" @click="applyDateRange">查询</el-button>
+        <el-button v-if="canExport" :loading="exporting" @click="exportReport">导出 Excel</el-button>
      </div>
    </section>

@@ -207,11 +253,18 @@ function formatInputDate(value: Date) {
        <div><h3>用户交互记录</h3><p>选择用户后，可查看选定时间范围内的完整关键操作流程。</p></div>
        <div class="user-search"><el-input v-model="keyword" clearable placeholder="姓名或手机号" @keyup.enter="searchUsers" /><el-button type="primary" @click="searchUsers">搜索</el-button></div>
      </div>
-      <el-table v-loading="usersLoading" :data="users" stripe empty-text="当前范围暂无用户行为记录">
-        <el-table-column prop="userName" label="用户" min-width="150" />
-        <el-table-column prop="phone" label="手机号" width="150" />
-        <el-table-column prop="eventCount" label="交互次数" width="120" align="center" />
-        <el-table-column label="最后交互时间" width="190"><template #default="{ row }">{{ formatTime(row.lastEventAt) }}</template></el-table-column>
+      <el-table
+        v-loading="usersLoading"
+        :data="users"
+        :default-sort="{ prop: userSortBy, order: userSortOrder === 'asc' ? 'ascending' : 'descending' }"
+        stripe
+        empty-text="当前范围暂无用户行为记录"
+        @sort-change="changeUserSort"
+      >
+        <el-table-column prop="userName" label="用户" min-width="150" sortable="custom" />
+        <el-table-column prop="phone" label="手机号" width="150" sortable="custom" />
+        <el-table-column prop="eventCount" label="交互次数" width="120" align="center" sortable="custom" />
+        <el-table-column prop="lastEventAt" label="最后交互时间" width="190" sortable="custom"><template #default="{ row }">{{ formatDateTime(row.lastEventAt) }}</template></el-table-column>
        <el-table-column label="操作" width="120" fixed="right"><template #default="{ row }"><el-button link type="primary" @click="openTimeline(row)">查看流程</el-button></template></el-table-column>
      </el-table>
      <AdminPagination v-if="userTotal" :page="userPage" :page-size="userPageSize" :total="userTotal" @change="changeUserPage" />
@@ -227,7 +280,7 @@ function formatInputDate(value: Date) {
          <article v-for="item in timeline.items" :key="item.id">
            <i :class="item.eventType" />
            <div>
-              <time>{{ formatTime(item.occurredAt) }}</time>
+              <time>{{ formatDateTime(item.occurredAt) }}</time>
              <strong>{{ item.eventName }}</strong>
              <small>{{ eventTypeLabel(item.eventType) }}<template v-if="targetLabel(item.targetType, item.targetId)"> · {{ targetLabel(item.targetType, item.targetId) }}</template></small>
            </div>
--- a/ai_knowledge_base_v2/apps/admin-web/src/components/UserDetailDrawer.vue
+++ b/ai_knowledge_base_v2/apps/admin-web/src/components/UserDetailDrawer.vue
@@ -4,6 +4,7 @@ import { ref, watch } from "vue";

 import { api } from "../services/api";
 import type { AdminUserDetail } from "../types/api";
+import { formatDateTime } from "../utils/dateTime";

 const props = defineProps<{ modelValue: boolean; userId: number | null }>();
 defineEmits<{ "update:modelValue": [value: boolean] }>();
@@ -171,11 +172,11 @@ function reportTriggerLabel(value: string) {
          </div>
          <div>
            <span>最近登录</span
-            ><strong>{{ detail.user.lastLoginAt || "-" }}</strong>
+            ><strong>{{ formatDateTime(detail.user.lastLoginAt) }}</strong>
          </div>
          <div>
            <span>最近发言</span
-            ><strong>{{ detail.metrics.lastMessageAt || "-" }}</strong>
+            ><strong>{{ formatDateTime(detail.metrics.lastMessageAt) }}</strong>
          </div>
          <div>
            <span>生成记录</span
@@ -265,9 +266,9 @@ function reportTriggerLabel(value: string) {
                    report.maxAttempts
                  }}</span
                >
-                <span v-if="report.nextRunAt"
-                  >下次执行：{{ report.nextRunAt }}</span
-                ><span>完成时间：{{ report.finishedAt || "-" }}</span>
+              <span v-if="report.nextRunAt"
+                >下次执行：{{ formatDateTime(report.nextRunAt) }}</span
+                ><span>完成时间：{{ formatDateTime(report.finishedAt) }}</span>
              </div>
              <p v-if="report.errorMessage" class="report-error">
                最近错误：{{ report.errorMessage }}
@@ -303,8 +304,8 @@ function reportTriggerLabel(value: string) {
                <span
                  >Token：{{ topic.tokenInput }}/{{ topic.tokenOutput }}</span
                >
-                <span>开始：{{ topic.startedAt }}</span
-                ><span>更新：{{ topic.updatedAt }}</span>
+                <span>开始：{{ formatDateTime(topic.startedAt) }}</span
+                ><span>更新：{{ formatDateTime(topic.updatedAt) }}</span>
              </div>
              <template v-if="topic.summary">
                <div class="topic-summary-meta">
@@ -319,10 +320,10 @@ function reportTriggerLabel(value: string) {
                    }}</span
                  >
                  <span v-if="topic.summary.lastStartedAt"
-                    >开始执行：{{ topic.summary.lastStartedAt }}</span
+                    >开始执行：{{ formatDateTime(topic.summary.lastStartedAt) }}</span
                  >
                  <span v-if="topic.summary.finishedAt"
-                    >完成：{{ topic.summary.finishedAt }}</span
+                    >完成：{{ formatDateTime(topic.summary.finishedAt) }}</span
                  >
                </div>
                <p v-if="topic.summary.errorMessage" class="report-error">
@@ -392,8 +393,8 @@ function reportTriggerLabel(value: string) {
          >
            <section class="topic-summary-card">
              <div class="topic-summary-meta">
-                <span>生成：{{ card.createdAt }}</span
-                ><span>复制：{{ card.copiedAt || "-" }}</span
+                <span>生成：{{ formatDateTime(card.createdAt) }}</span
+                ><span>复制：{{ formatDateTime(card.copiedAt) }}</span
                ><span>来源：{{ card.source }}</span>
              </div>
              <pre>{{ card.content }}</pre>
@@ -420,8 +421,8 @@ function reportTriggerLabel(value: string) {
          >
            <section class="topic-summary-card">
              <div class="topic-summary-meta">
-                <span>生成：{{ draft.createdAt }}</span
-                ><span>复制：{{ draft.copiedAt || "-" }}</span
+                <span>生成：{{ formatDateTime(draft.createdAt) }}</span
+                ><span>复制：{{ formatDateTime(draft.copiedAt) }}</span
                ><span>来源：{{ draft.source }}</span>
              </div>
              <pre>{{ draft.content }}</pre>
--- a/ai_knowledge_base_v2/apps/admin-web/src/components/UserManagementView.vue
+++ b/ai_knowledge_base_v2/apps/admin-web/src/components/UserManagementView.vue
@@ -12,6 +12,7 @@ import AdminPagination from "./AdminPagination.vue";
 import TableRowActions from "./TableRowActions.vue";
 import UserDetailDrawer from "./UserDetailDrawer.vue";
 import UserEntitlementRenewDialog from "./UserEntitlementRenewDialog.vue";
+import { formatDate, formatDateTime, toUtcIsoFromBusinessDate } from "../utils/dateTime";

 const loading = ref(false);
 const users = ref<AdminUser[]>([]);
@@ -150,14 +151,6 @@ function entitlementStatusType(row: AdminUser) {
  return "info";
 }

-function formatEntitlementDate(value?: string | null) {
-  if (!value) return "长期";
-  const date = new Date(value);
-  return Number.isNaN(date.getTime())
-    ? value
-    : date.toLocaleDateString("zh-CN");
-}
-
 async function assignUserEntitlement(row: AdminUser, planId: number) {
  row.entitlement = await api.assignUserEntitlement(row.id, { planId });
  ElMessage.success("用户权益已更新");
@@ -186,9 +179,7 @@ async function createStudent() {
    nickname: studentForm.nickname || null,
    status: studentForm.status,
    dailyChatLimit: studentForm.dailyChatLimit,
-    expiredAt: studentForm.expiredAt
-      ? `${studentForm.expiredAt}T23:59:59`
-      : null,
+    expiredAt: toUtcIsoFromBusinessDate(studentForm.expiredAt, "end") ?? null,
  });
  ElMessage.success("学员已添加");
  resetStudentForm();
@@ -412,8 +403,8 @@ async function deleteUser(row: AdminUser) {
              >{{ row.entitlement?.name || "默认基础版" }} ·
              {{
                row.entitlement?.lifecycleStatus === "expired_fallback"
-                  ? `原 ${row.entitlement?.previousPlanName || "权益"} ${formatEntitlementDate(row.entitlement?.previousExpiredAt)} 到期`
-                  : `有效至 ${formatEntitlementDate(row.entitlement?.expiredAt)}`
+                  ? `原 ${row.entitlement?.previousPlanName || "权益"} ${formatDate(row.entitlement?.previousExpiredAt, "长期")} 到期`
+                  : `有效至 ${formatDate(row.entitlement?.expiredAt, "长期")}`
              }}</small
            >
            <div class="entitlement-meta-row">
@@ -424,7 +415,7 @@ async function deleteUser(row: AdminUser) {
          </div>
        </template>
      </el-table-column>
-      <el-table-column prop="lastLoginAt" label="最近登录" width="180" />
+      <el-table-column label="最近登录" width="180"><template #default="{ row }">{{ formatDateTime(row.lastLoginAt) }}</template></el-table-column>
      <el-table-column label="操作" width="210" fixed="right">
        <template #default="{ row }">
          <TableRowActions>
--- a/ai_knowledge_base_v2/apps/admin-web/src/services/api.ts
+++ b/ai_knowledge_base_v2/apps/admin-web/src/services/api.ts
@@ -159,10 +159,15 @@ export const api = {
    request<PeakTrafficResult>(`/admin/dashboard/traffic${queryString({ grain })}`),
  userBehaviorOverview: (query: { start?: string; end?: string } = {}) =>
    request<UserBehaviorOverview>(`/admin/user-behavior/overview${queryString(query)}`),
-  userBehaviorUsers: (query: { start?: string; end?: string; keyword?: string; page?: number; pageSize?: number } = {}) =>
+  userBehaviorUsers: (query: { start?: string; end?: string; keyword?: string; page?: number; pageSize?: number; sortBy?: string; sortOrder?: "asc" | "desc" } = {}) =>
    request<PageResult<UserBehaviorUserSummary>>(`/admin/user-behavior/users${queryString(query)}`),
  userBehaviorTimeline: (userId: number, query: { start?: string; end?: string; page?: number; pageSize?: number } = {}) =>
    request<UserBehaviorTimeline>(`/admin/user-behavior/user/${userId}/timeline${queryString(query)}`),
+  exportUserBehavior: (query: { start?: string; end?: string; keyword?: string; sortBy?: string; sortOrder?: "asc" | "desc" } = {}) =>
+    download(
+      `/admin/user-behavior/export${queryString(query)}`,
+      `用户行为分析_${query.start || "开始"}_${query.end || "当前"}.xlsx`,
+    ),
  users: (query: { keyword?: string; planId?: number; entitlementStatus?: string; page?: number; pageSize?: number } = {}) => request<PageResult<AdminUser>>(`/admin/user/list${queryString(query)}`),
  userDetail: (id: number) => request<AdminUserDetail>(`/admin/user/${id}/detail`),
  userTopics: (id: number, query: { keyword?: string; page?: number; pageSize?: number } = {}) =>
@@ -335,10 +340,12 @@ export const api = {
  ssoAudits: (query: { clientId?: number; auditStatus?: string; page?: number; pageSize?: number } = {}) =>
    request<PageResult<SsoAuditItem>>(`/admin/sso/audit/list${queryString(query)}`),
  chats: (query: ChatRecordQuery = {}) => request<PageResult<ChatRecord>>(`/admin/chat/list${queryString(query)}`),
-  chatDetail: (sessionId: number, query: { messagePage?: number; messagePageSize?: number } = {}) =>
+  chatDetail: (sessionId: number, query: { messagePage?: number; messagePageSize?: number; focusMessageId?: number } = {}) =>
    request<ChatDetail>(`/admin/chat/${sessionId}${queryString(query)}`),
  chatMessages: (sessionId: number, query: { page?: number; pageSize?: number } = {}) =>
    request<PageResult<ChatMessageRecord>>(`/admin/chat/${sessionId}/messages${queryString(query)}`),
+  exportChatDetail: (sessionId: number, filename = `完整对话_会话${sessionId}.xlsx`) =>
+    download(`/admin/chat/${sessionId}/export`, filename),
  exportChats: (query: ChatRecordQuery = {}) => download(`/admin/chat/export${queryString(query)}`, "chat_records.csv"),
  aiLogs: (query: { sessionId?: number; userId?: number; status?: string; page?: number; pageSize?: number } = {}) =>
    request<PageResult<AiLogRecord>>(`/admin/ai-log/list${queryString(query)}`),
@@ -359,7 +366,7 @@ export const api = {
  saveRetrievalRetention: (retentionDays: number | null) => request<{ enabled: boolean; retentionDays: number | null }>("/admin/retrieval-log/retention", { method: "PUT", body: JSON.stringify({ retentionDays }) }),
  storageStats: (refresh = false) => request<Record<string, any>>(`/admin/dashboard/storage${refresh ? "?refresh=true" : ""}`),
  retrievalLogDetail: (id: number) => request<Record<string, unknown>>(`/admin/retrieval-log/${id}`),
-  attentionList: (query: { page?: number; pageSize?: number } = {}) => request<PageResult<AttentionItem>>(`/admin/attention/list${queryString(query)}`),
+  attentionList: (query: { priority?: string; status?: string; dateFrom?: string; dateTo?: string; page?: number; pageSize?: number } = {}) => request<PageResult<AttentionItem>>(`/admin/attention/list${queryString(query)}`),
  attentionConfig: () => request<AttentionConfig>("/admin/attention/config"),
  attentionPreviewConfig: () => request<AttentionConfig>("/admin/attention/preview/config"),
  saveAttentionConfig: (payload: AttentionConfig) => request<AttentionConfig>("/admin/attention/config", { method: "PUT", body: JSON.stringify(payload) }),
--- a/ai_knowledge_base_v2/apps/admin-web/src/types/api.ts
+++ b/ai_knowledge_base_v2/apps/admin-web/src/types/api.ts
@@ -608,6 +608,7 @@ export interface AttentionItem {
  priority: string;
  status: string;
  handlerNote?: string | null;
+  targetAvailable?: boolean;
  createdAt: string;
 }

@@ -725,6 +726,7 @@ export interface ChatDetail {
  session: ChatRecord;
  messages: ChatMessageRecord[];
  messagesPage?: PageResult<ChatMessageRecord>;
+  focusedMessageId?: number | null;
  aiLogs: AiLogRecord[];
  topics?: TopicSessionRecord[];
  helpCards?: TeacherHelpCardRecord[];
--- a/ai_knowledge_base_v2/apps/admin-web/src/utils/dateTime.ts
+++ b/ai_knowledge_base_v2/apps/admin-web/src/utils/dateTime.ts
@@ -0,0 +1,81 @@
+export const BUSINESS_TIME_ZONE = "Asia/Shanghai";
+const BUSINESS_OFFSET = "+08:00";
+const DATE_ONLY_PATTERN = /^\d{4}-\d{2}-\d{2}$/;
+const EXPLICIT_OFFSET_PATTERN = /(?:Z|[+-]\d{2}:?\d{2})$/i;
+
+export function parseApiDateTime(value?: string | Date | null): Date | null {
+  if (!value) return null;
+  if (value instanceof Date) {
+    return Number.isNaN(value.getTime()) ? null : value;
+  }
+  const text = value.trim();
+  if (!text) return null;
+  const isoText = text.includes(" ") ? text.replace(" ", "T") : text;
+  const normalized = DATE_ONLY_PATTERN.test(isoText)
+    ? `${isoText}T00:00:00${BUSINESS_OFFSET}`
+    : EXPLICIT_OFFSET_PATTERN.test(isoText)
+      ? isoText
+      : `${isoText}Z`;
+  const parsed = new Date(normalized);
+  return Number.isNaN(parsed.getTime()) ? null : parsed;
+}
+
+function businessParts(value?: string | Date | null) {
+  const parsed = parseApiDateTime(value);
+  if (!parsed) return null;
+  const parts = new Intl.DateTimeFormat("zh-CN", {
+    timeZone: BUSINESS_TIME_ZONE,
+    year: "numeric",
+    month: "2-digit",
+    day: "2-digit",
+    hour: "2-digit",
+    minute: "2-digit",
+    second: "2-digit",
+    hour12: false,
+    hourCycle: "h23",
+  }).formatToParts(parsed);
+  return Object.fromEntries(parts.map((part) => [part.type, part.value]));
+}
+
+export function formatDateTime(
+  value?: string | Date | null,
+  fallback = "-",
+): string {
+  const parts = businessParts(value);
+  if (!parts) return fallback;
+  return `${parts.year}-${parts.month}-${parts.day} ${parts.hour}:${parts.minute}:${parts.second}`;
+}
+
+export function formatDate(
+  value?: string | Date | null,
+  fallback = "-",
+): string {
+  const parts = businessParts(value);
+  if (!parts) return fallback;
+  return `${parts.year}-${parts.month}-${parts.day}`;
+}
+
+export function formatTime(
+  value?: string | Date | null,
+  fallback = "-",
+): string {
+  const parts = businessParts(value);
+  if (!parts) return fallback;
+  return `${parts.hour}:${parts.minute}`;
+}
+
+export function toUtcIsoFromBusinessDate(
+  value: string,
+  boundary: "start" | "end" = "start",
+): string | undefined {
+  if (!DATE_ONLY_PATTERN.test(value)) return undefined;
+  const localTime = boundary === "start" ? "00:00:00.000" : "23:59:59.999";
+  return new Date(`${value}T${localTime}${BUSINESS_OFFSET}`).toISOString();
+}
+
+export function toUtcIsoFromBusinessDateTime(value: string): string | undefined {
+  if (!value) return undefined;
+  const normalized = value.length === 16 ? `${value}:00` : value;
+  const parsed = new Date(`${normalized}${BUSINESS_OFFSET}`);
+  return Number.isNaN(parsed.getTime()) ? undefined : parsed.toISOString();
+}
--- a/ai_knowledge_base_v2/apps/backend/alembic/versions/0040_human_attention_filters.py
+++ b/ai_knowledge_base_v2/apps/backend/alembic/versions/0040_human_attention_filters.py
@@ -0,0 +1,25 @@
+"""add human attention time filter index
+
+Revision ID: 0040_attention_filters
+Revises: 0039_attention_config
+"""
+
+from alembic import op
+
+
+revision = "0040_attention_filters"
+down_revision = "0039_attention_config"
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    op.create_index(
+        "ix_human_attention_created",
+        "sys_human_attention_record",
+        ["created_at", "id"],
+    )
+
+
+def downgrade() -> None:
+    op.drop_index("ix_human_attention_created", table_name="sys_human_attention_record")
--- a/ai_knowledge_base_v2/apps/backend/alembic/versions/0041_utc_time_contract.py
+++ b/ai_knowledge_base_v2/apps/backend/alembic/versions/0041_utc_time_contract.py
@@ -0,0 +1,87 @@
+"""normalize legacy server timestamps to UTC
+
+Revision ID: 0041_utc_time_contract
+Revises: 0040_attention_filters
+"""
+
+from alembic import op
+from sqlalchemy import text
+
+
+revision = "0041_utc_time_contract"
+down_revision = "0040_attention_filters"
+branch_labels = None
+depends_on = None
+
+
+# Columns populated by MySQL CURRENT_TIMESTAMP. Fields that application
+# services already wrote explicitly in UTC are intentionally excluded.
+SERVER_TIMESTAMP_COLUMNS: dict[str, tuple[str, ...]] = {
+    "sys_admin": ("created_at", "updated_at"),
+    "sys_agent_batch_test": ("created_at", "updated_at"),
+    "sys_agent_batch_test_item": ("created_at", "updated_at"),
+    "sys_ai_request_log": ("created_at",),
+    "sys_chat_session": ("created_at", "updated_at"),
+    "sys_content_generation_config": ("updated_at",),
+    "sys_entitlement_plan": ("created_at", "updated_at"),
+    "sys_growth_profile_revision": ("created_at",),
+    "sys_human_attention_history": ("created_at",),
+    "sys_human_attention_job": ("created_at",),
+    "sys_human_attention_record": ("created_at", "updated_at"),
+    "sys_knowledge": ("created_at", "updated_at"),
+    "sys_knowledge_publish_log": ("created_at",),
+    "sys_knowledge_retrieval_log": ("created_at",),
+    "sys_knowledge_review_record": ("created_at",),
+    "sys_knowledge_sync_job": ("created_at",),
+    "sys_knowledge_version": ("created_at",),
+    "sys_log_retention_policy": ("updated_at",),
+    "sys_message_feedback": ("created_at",),
+    "sys_operation_log": ("created_at",),
+    "sys_periodic_report": ("created_at", "updated_at"),
+    "sys_prompt": ("updated_at",),
+    "sys_question_insight_cleaned_question": ("created_at", "updated_at"),
+    "sys_role": ("created_at", "updated_at"),
+    "sys_share_draft": ("created_at",),
+    "sys_sso_client": ("created_at", "updated_at"),
+    "sys_sso_login_audit": ("created_at",),
+    "sys_storage_snapshot": ("created_at",),
+    "sys_system_config": ("updated_at",),
+    "sys_teacher_help_card": ("created_at",),
+    "sys_topic_session": ("created_at", "updated_at"),
+    "sys_topic_summary": ("created_at", "updated_at"),
+    "sys_user": ("created_at", "updated_at"),
+    "sys_user_behavior_event": ("created_at",),
+    "sys_user_entitlement": ("created_at", "updated_at"),
+    "sys_user_external_identity": ("created_at", "updated_at"),
+    "sys_user_growth_profile": ("created_at", "updated_at"),
+    "sys_user_kb": ("created_at", "updated_at"),
+}
+
+
+def _server_offset_seconds() -> int:
+    connection = op.get_bind()
+    if connection.dialect.name != "mysql":
+        return 0
+    return int(connection.scalar(text("SELECT TIMESTAMPDIFF(SECOND, UTC_TIMESTAMP(), NOW())")) or 0)
+
+
+def _shift_server_timestamps(offset_seconds: int) -> None:
+    if not offset_seconds:
+        return
+    connection = op.get_bind()
+    operation = "SUB" if offset_seconds > 0 else "ADD"
+    seconds = abs(offset_seconds)
+    for table_name, columns in SERVER_TIMESTAMP_COLUMNS.items():
+        assignments = ", ".join(
+            f"`{column}` = DATE_{operation}(`{column}`, INTERVAL {seconds} SECOND)"
+            for column in columns
+        )
+        connection.execute(text(f"UPDATE `{table_name}` SET {assignments}"))
+
+
+def upgrade() -> None:
+    _shift_server_timestamps(_server_offset_seconds())
+
+
+def downgrade() -> None:
+    _shift_server_timestamps(-_server_offset_seconds())
--- a/ai_knowledge_base_v2/apps/backend/alembic/versions/0042_record_export_permission.py
+++ b/ai_knowledge_base_v2/apps/backend/alembic/versions/0042_record_export_permission.py
@@ -0,0 +1,48 @@
+"""add granular record export permission
+
+Revision ID: 0042_record_export_permission
+Revises: 0041_utc_time_contract
+"""
+
+from __future__ import annotations
+
+import json
+
+from alembic import op
+from sqlalchemy import text
+
+
+revision = "0042_record_export_permission"
+down_revision = "0041_utc_time_contract"
+branch_labels = None
+depends_on = None
+
+
+def _rewrite_permissions(*, add_export: bool) -> None:
+    connection = op.get_bind()
+    rows = connection.execute(text("SELECT id, permissions FROM sys_role")).mappings().all()
+    for row in rows:
+        try:
+            permissions = list(json.loads(row["permissions"] or "[]"))
+        except (TypeError, ValueError, json.JSONDecodeError):
+            continue
+        changed = False
+        if add_export and "records.view" in permissions and "records.export" not in permissions:
+            permissions.append("records.export")
+            changed = True
+        if not add_export and "records.export" in permissions:
+            permissions = [item for item in permissions if item != "records.export"]
+            changed = True
+        if changed:
+            connection.execute(
+                text("UPDATE sys_role SET permissions = :permissions WHERE id = :role_id"),
+                {"permissions": json.dumps(sorted(set(permissions))), "role_id": row["id"]},
+            )
+
+
+def upgrade() -> None:
+    _rewrite_permissions(add_export=True)
+
+
+def downgrade() -> None:
+    _rewrite_permissions(add_export=False)
--- a/ai_knowledge_base_v2/apps/backend/app/api/admin_agent_records.py
+++ b/ai_knowledge_base_v2/apps/backend/app/api/admin_agent_records.py
@@ -10,7 +10,9 @@ from sqlalchemy.orm import Session
 from app.core.database import get_db
 from app.core.dependencies import get_current_admin
 from app.core.responses import api_success
+from app.core.time_utils import as_utc_naive, business_day_boundary
 from app.models.admin import Admin
+from app.models.chat import ChatMessage
 from app.models.knowledge import (
    HumanAttentionHistory,
    HumanAttentionRecord,
@@ -95,7 +97,9 @@ def _cleanup_before(payload: dict) -> datetime:
    if not raw:
        raise HTTPException(status_code=400, detail="必须指定清理日期")
    try:
-        return datetime.fromisoformat(raw.replace("Z", "+00:00")).replace(tzinfo=None)
+        if len(raw) == 10:
+            return business_day_boundary(datetime.fromisoformat(raw).date())
+        return as_utc_naive(datetime.fromisoformat(raw.replace("Z", "+00:00")))
    except ValueError as exc:
        raise HTTPException(status_code=400, detail="清理日期格式错误") from exc

@@ -151,21 +155,46 @@ def _knowledge_type_label(value: str) -> str:

@router.get("/attention/list")
 def attention_list(
-    priority: str = Query(default=""),
-    statusValue: str = Query(default="", alias="status"),
+    priority: str = Query(default="", pattern="^(|urgent|important|normal)$"),
+    statusValue: str = Query(default="", alias="status", pattern="^(|pending|processing|resolved|ignored)$"),
+    dateFrom: datetime | None = Query(default=None),
+    dateTo: datetime | None = Query(default=None),
    page: int = Query(default=1, ge=1),
    pageSize: int = Query(default=20, ge=10, le=100),
    db: Session = Depends(get_db),
    current_admin: Admin = Depends(get_current_admin),
 ) -> dict:
+    dateFrom = as_utc_naive(dateFrom) if dateFrom is not None else None
+    dateTo = as_utc_naive(dateTo) if dateTo is not None else None
+    if dateFrom is not None and dateTo is not None and dateFrom > dateTo:
+        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail="开始时间不能晚于结束时间")
    query = select(HumanAttentionRecord)
    if priority:
        query = query.where(HumanAttentionRecord.priority == priority)
    if statusValue:
        query = query.where(HumanAttentionRecord.status == statusValue)
+    if dateFrom is not None:
+        query = query.where(HumanAttentionRecord.created_at >= dateFrom)
+    if dateTo is not None:
+        query = query.where(HumanAttentionRecord.created_at <= dateTo)
    total = db.scalar(select(func.count()).select_from(query.subquery())) or 0
    rows = db.scalars(query.order_by(HumanAttentionRecord.id.desc()).offset((page - 1) * pageSize).limit(pageSize)).all()
-    return api_success(page_result([_attention_dict(item) for item in rows], total=total, page=page, page_size=pageSize))
+    message_keys = {
+        (message_id, session_id)
+        for message_id, session_id in db.execute(
+            select(ChatMessage.id, ChatMessage.session_id).where(
+                ChatMessage.id.in_([item.message_id for item in rows])
+            )
+        ).all()
+    } if rows else set()
+    items = [
+        _attention_dict(
+            item,
+            target_available=(item.message_id, item.session_id) in message_keys,
+        )
+        for item in rows
+    ]
+    return api_success(page_result(items, total=total, page=page, page_size=pageSize))


@router.put("/attention/{attention_id}")
@@ -251,8 +280,8 @@ def _retrieval_dict(item: KnowledgeRetrievalLog, *, detail: bool) -> dict:
    return data


-def _attention_dict(item: HumanAttentionRecord) -> dict:
-    return {
+def _attention_dict(item: HumanAttentionRecord, *, target_available: bool | None = None) -> dict:
+    data = {
        "id": item.id,
        "sessionId": item.session_id,
        "messageId": item.message_id,
@@ -267,6 +296,9 @@ def _attention_dict(item: HumanAttentionRecord) -> dict:
        "createdAt": item.created_at,
        "updatedAt": item.updated_at,
    }
+    if target_available is not None:
+        data["targetAvailable"] = target_available
+    return data


 def _json(raw: str | None):
--- a/ai_knowledge_base_v2/apps/backend/app/api/admin_dashboard.py
+++ b/ai_knowledge_base_v2/apps/backend/app/api/admin_dashboard.py
@@ -18,6 +18,7 @@ from app.services.admin_service import AdminDashboardService
 from app.models.logs import StorageSnapshot
 from app.services.redis_client import get_sync_redis_client
 from app.services.request_traffic_service import RequestTrafficService
+from app.core.time_utils import business_day_boundary

 router = APIRouter()

@@ -29,12 +30,8 @@ def dashboard(
    db: Session = Depends(get_db),
    current_admin: Admin = Depends(get_current_admin),
 ) -> dict:
-    start_dt = datetime.strptime(start, "%Y-%m-%d") if start else None
-    if end:
-        end_dt = datetime.strptime(end, "%Y-%m-%d")
-        end_dt = end_dt.replace(hour=23, minute=59, second=59)
-    else:
-        end_dt = None
+    start_dt = business_day_boundary(datetime.strptime(start, "%Y-%m-%d").date()) if start else None
+    end_dt = business_day_boundary(datetime.strptime(end, "%Y-%m-%d").date(), end_exclusive=True) if end else None
    stats = AdminDashboardService.stats(db, start_dt, end_dt)
    return api_success(DashboardStats.model_validate(stats).model_dump())

--- a/ai_knowledge_base_v2/apps/backend/app/api/admin_records.py
+++ b/ai_knowledge_base_v2/apps/backend/app/api/admin_records.py
@@ -14,6 +14,7 @@ from sqlalchemy.orm import Session, load_only
 from app.core.database import get_db
 from app.core.dependencies import get_current_admin
 from app.core.responses import api_success
+from app.core.time_utils import as_utc_naive, to_business_naive
 from app.models.admin import Admin
 from app.models.chat import ChatMessage, ChatSession, TopicSession
 from app.models.growth import ShareDraft, TeacherHelpCard, TopicSummary
@@ -27,6 +28,7 @@ from app.services.question_insight_export_service import QuestionInsightExportSe
 from app.services.growth_profile_service import topic_dict, topic_summary_dict
 from app.services.help_card_service import help_card_dict
 from app.services.share_draft_service import share_draft_dict
+from app.services.chat_export_service import ChatExportService

 router = APIRouter()

@@ -45,6 +47,8 @@ def chat_list(
    db: Session = Depends(get_db),
    current_admin: Admin = Depends(get_current_admin),
 ) -> dict:
+    dateFrom = as_utc_naive(dateFrom) if dateFrom is not None else None
+    dateTo = as_utc_naive(dateTo) if dateTo is not None else None
    query = _chat_query(
        keyword=keyword,
        user_id=userId,
@@ -72,6 +76,8 @@ def export_chats(
    db: Session = Depends(get_db),
    current_admin: Admin = Depends(get_current_admin),
 ) -> Response:
+    dateFrom = as_utc_naive(dateFrom) if dateFrom is not None else None
+    dateTo = as_utc_naive(dateTo) if dateTo is not None else None
    rows = db.execute(
        _chat_query(
            keyword=keyword,
@@ -98,8 +104,8 @@ def export_chats(
                source_client.name if source_client else "千问千答直接访问",
                session.title,
                session.message_count,
-                session.last_message_at,
-                session.updated_at,
+                to_business_naive(session.last_message_at),
+                to_business_naive(session.updated_at),
            ]
        )
    content = "\ufeff" + output.getvalue()
@@ -132,11 +138,53 @@ def chat_messages(
    return api_success(page_result([_message_dict(item) for item in messages], total=total, page=page, page_size=pageSize))


+@router.get("/chat/{session_id}/export")
+def export_chat_detail(
+    session_id: int,
+    db: Session = Depends(get_db),
+    current_admin: Admin = Depends(get_current_admin),
+) -> StreamingResponse:
+    session_row = db.execute(
+        select(ChatSession, User, SsoClient)
+        .join(User, User.id == ChatSession.user_id, isouter=True)
+        .join(SsoClient, SsoClient.id == ChatSession.source_client_id, isouter=True)
+        .where(ChatSession.id == session_id)
+    ).first()
+    if session_row is None:
+        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="会话不存在")
+    session, user, source_client = session_row
+    messages = db.scalars(
+        select(ChatMessage)
+        .where(ChatMessage.session_id == session_id)
+        .order_by(ChatMessage.created_at.asc(), ChatMessage.id.asc())
+    ).all()
+    stream = ChatExportService.build(
+        session=session,
+        user=user,
+        source_name=source_client.name if source_client else "千问千答直接访问",
+        messages=messages,
+    )
+    OperationLogService.write(
+        db,
+        admin_id=current_admin.id,
+        module="records",
+        action="export_chat_detail",
+        target_id=session.id,
+    )
+    db.commit()
+    return StreamingResponse(
+        stream,
+        media_type="application/vnd.openxmlformats-officedocument.spreadsheetml.sheet",
+        headers={"Content-Disposition": f'attachment; filename="chat_session_{session.id}.xlsx"'},
+    )
+
+
@router.get("/chat/{session_id}")
 def chat_detail(
    session_id: int,
    messagePage: int = Query(default=1, ge=1),
    messagePageSize: int = Query(default=20, ge=10, le=100),
+    focusMessageId: int | None = Query(default=None, gt=0),
    db: Session = Depends(get_db),
    current_admin: Admin = Depends(get_current_admin),
 ) -> dict:
@@ -154,6 +202,28 @@ def chat_detail(
    session, user, source_client = session_row
    message_query = select(ChatMessage).where(ChatMessage.session_id == session_id)
    message_total = db.scalar(select(func.count()).select_from(message_query.subquery())) or 0
+    if focusMessageId is not None:
+        focused_message = db.scalar(
+            select(ChatMessage).where(
+                ChatMessage.id == focusMessageId,
+                ChatMessage.session_id == session_id,
+            )
+        )
+        if focused_message is None:
+            raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="触发消息不属于该会话或已不存在")
+        focused_position = db.scalar(
+            select(func.count()).select_from(ChatMessage).where(
+                ChatMessage.session_id == session_id,
+                or_(
+                    ChatMessage.created_at < focused_message.created_at,
+                    (
+                        (ChatMessage.created_at == focused_message.created_at)
+                        & (ChatMessage.id <= focused_message.id)
+                    ),
+                ),
+            )
+        ) or 1
+        messagePage = (focused_position - 1) // messagePageSize + 1
    messages = db.scalars(
        message_query
        .order_by(ChatMessage.created_at.asc(), ChatMessage.id.asc())
@@ -198,6 +268,7 @@ def chat_detail(
            "topics": topics,
            "helpCards": [help_card_dict(item) for item in help_cards],
            "shareDrafts": [share_draft_dict(item) for item in share_drafts],
+            "focusedMessageId": focusMessageId,
        }
    )

@@ -288,6 +359,8 @@ def question_insights(
    db: Session = Depends(get_db),
    current_admin: Admin = Depends(get_current_admin),
 ) -> dict:
+    dateFrom = as_utc_naive(dateFrom) if dateFrom is not None else None
+    dateTo = as_utc_naive(dateTo) if dateTo is not None else None
    return api_success(
        QuestionInsightService.summarize(
            db,
@@ -309,6 +382,8 @@ def refresh_question_insights(
    db: Session = Depends(get_db),
    current_admin: Admin = Depends(get_current_admin),
 ) -> dict:
+    dateFrom = as_utc_naive(dateFrom) if dateFrom is not None else None
+    dateTo = as_utc_naive(dateTo) if dateTo is not None else None
    result = QuestionInsightService.refresh(
        db,
        date_from=dateFrom,
@@ -334,6 +409,8 @@ def export_question_insights(
    db: Session = Depends(get_db),
    current_admin: Admin = Depends(get_current_admin),
 ) -> StreamingResponse:
+    dateFrom = as_utc_naive(dateFrom) if dateFrom is not None else None
+    dateTo = as_utc_naive(dateTo) if dateTo is not None else None
    if dateFrom is not None and dateTo is not None and dateFrom > dateTo:
        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail="开始时间不能晚于结束时间")
    result = QuestionInsightService.summarize(
@@ -387,9 +464,9 @@ def _chat_query(
    if source_client_id is not None:
        query = query.where(ChatSession.source_type == "sso", ChatSession.source_client_id == source_client_id)
    if date_from is not None:
-        query = query.where(ChatSession.updated_at >= date_from.replace(tzinfo=None))
+        query = query.where(ChatSession.updated_at >= date_from)
    if date_to is not None:
-        query = query.where(ChatSession.updated_at <= date_to.replace(tzinfo=None))
+        query = query.where(ChatSession.updated_at <= date_to)
    if status:
        query = query.where(
            exists()
--- a/ai_knowledge_base_v2/apps/backend/app/api/admin_user_behavior.py
+++ b/ai_knowledge_base_v2/apps/backend/app/api/admin_user_behavior.py
@@ -3,12 +3,15 @@ from __future__ import annotations
 from datetime import date

 from fastapi import APIRouter, Depends, HTTPException, Query, status
+from fastapi.responses import Response
 from sqlalchemy.orm import Session

 from app.core.database import get_db
 from app.core.dependencies import get_current_admin
 from app.core.responses import api_success
 from app.models.admin import Admin
+from app.services.admin_service import OperationLogService
+from app.services.user_behavior_export_service import UserBehaviorExportService
 from app.services.user_behavior_service import UserBehaviorService


@@ -30,6 +33,8 @@ def behavior_users(
    start: date | None = Query(default=None),
    end: date | None = Query(default=None),
    keyword: str = Query(default="", max_length=50),
+    sortBy: str = Query(default="lastEventAt", pattern="^(userName|phone|eventCount|lastEventAt)$"),
+    sortOrder: str = Query(default="desc", pattern="^(asc|desc)$"),
    page: int = Query(default=1, ge=1),
    pageSize: int = Query(default=20, ge=5, le=100),
    db: Session = Depends(get_db),
@@ -43,10 +48,42 @@ def behavior_users(
            keyword=keyword,
            page=page,
            page_size=pageSize,
+            sort_by=sortBy,
+            sort_order=sortOrder,
        )
    )


+@router.get("/user-behavior/export")
+def export_behavior_report(
+    start: date | None = Query(default=None),
+    end: date | None = Query(default=None),
+    keyword: str = Query(default="", max_length=50),
+    sortBy: str = Query(default="lastEventAt", pattern="^(userName|phone|eventCount|lastEventAt)$"),
+    sortOrder: str = Query(default="desc", pattern="^(asc|desc)$"),
+    db: Session = Depends(get_db),
+    current_admin: Admin = Depends(get_current_admin),
+) -> Response:
+    stream = UserBehaviorExportService.build_workbook(
+        db,
+        start=start,
+        end=end,
+        keyword=keyword,
+        sort_by=sortBy,
+        sort_order=sortOrder,
+    )
+    OperationLogService.write(db, admin_id=current_admin.id, module="behavior", action="export")
+    db.commit()
+    start_label = start.isoformat() if start else "default"
+    end_label = end.isoformat() if end else "today"
+    filename = f"user_behavior_report_{start_label}_{end_label}.xlsx"
+    return Response(
+        content=stream.getvalue(),
+        media_type="application/vnd.openxmlformats-officedocument.spreadsheetml.sheet",
+        headers={"Content-Disposition": f'attachment; filename="{filename}"'},
+    )
+
+
@router.get("/user-behavior/user/{user_id}/timeline")
 def behavior_timeline(
    user_id: int,
--- a/ai_knowledge_base_v2/apps/backend/app/api/admin_users.py
+++ b/ai_knowledge_base_v2/apps/backend/app/api/admin_users.py
@@ -17,6 +17,7 @@ from sqlalchemy.orm import Session
 from app.core.database import get_db
 from app.core.dependencies import get_current_admin
 from app.core.responses import api_success
+from app.core.time_utils import as_utc_naive, business_datetime_to_utc_naive, business_day_boundary
 from app.models.admin import Admin
 from app.models.ai_config import SystemConfig
 from app.models.entitlement import EntitlementPlan, UserEntitlement
@@ -475,7 +476,7 @@ def update_user(
    if payload.dailyChatLimit is not None:
        user.daily_chat_limit = payload.dailyChatLimit
    if payload.expiredAt is not None:
-        user.expired_at = payload.expiredAt.replace(tzinfo=None)
+        user.expired_at = as_utc_naive(payload.expiredAt)
    db.add(user)
    if payload.entitlementPlanId is not None:
        EntitlementService.assign_user_plan(
@@ -698,7 +699,7 @@ def _apply_user_payload(
    user.nickname = payload.nickname.strip() if payload.nickname else None
    user.status = payload.status
    user.daily_chat_limit = payload.dailyChatLimit if payload.dailyChatLimit is not None else default_daily_limit
-    user.expired_at = payload.expiredAt.replace(tzinfo=None) if payload.expiredAt is not None else None
+    user.expired_at = as_utc_naive(payload.expiredAt) if payload.expiredAt is not None else None


 def _default_daily_chat_limit(db: Session) -> int:
@@ -763,14 +764,17 @@ def _parse_optional_datetime(value: object | None) -> datetime | None:
    if value is None or _cell_text(value) == "":
        return None
    if isinstance(value, datetime):
-        return value.replace(tzinfo=None)
+        return business_datetime_to_utc_naive(value)
    if isinstance(value, date):
-        return datetime.combine(value, datetime.min.time())
+        return business_day_boundary(value, end_exclusive=True) - timedelta(microseconds=1)

    text = _cell_text(value)
    for fmt in ("%Y-%m-%d %H:%M:%S", "%Y-%m-%d", "%Y/%m/%d %H:%M:%S", "%Y/%m/%d"):
        try:
-            return datetime.strptime(text, fmt)
+            parsed = datetime.strptime(text, fmt)
+            if "%H" not in fmt:
+                return business_day_boundary(parsed.date(), end_exclusive=True) - timedelta(microseconds=1)
+            return business_datetime_to_utc_naive(parsed)
        except ValueError:
            continue
    raise ValueError("有效期格式应为 YYYY-MM-DD 或 YYYY-MM-DD HH:mm:ss")
--- a/ai_knowledge_base_v2/apps/backend/app/api/feedback.py
+++ b/ai_knowledge_base_v2/apps/backend/app/api/feedback.py
@@ -1,6 +1,6 @@
 from __future__ import annotations

-from datetime import UTC, date, datetime, time, timedelta
+from datetime import UTC, date, datetime, timedelta
 from io import BytesIO

 from fastapi import APIRouter, Depends, HTTPException, Query, status
@@ -18,6 +18,7 @@ from app.api.pagination import page_result
 from app.core.database import get_db
 from app.core.dependencies import get_current_admin, get_current_user
 from app.core.responses import api_success
+from app.core.time_utils import business_day_boundary, to_business_naive
 from app.models.admin import Admin
 from app.models.chat import ChatMessage, ChatSession
 from app.models.feedback import MessageFeedback
@@ -136,9 +137,9 @@ def _feedback_query(read_status: str, start_date: date | None, end_date: date |
    if read_status != "all":
        query = query.where(MessageFeedback.is_read == (1 if read_status == "read" else 0))
    if start_date is not None:
-        query = query.where(MessageFeedback.created_at >= datetime.combine(start_date, time.min))
+        query = query.where(MessageFeedback.created_at >= business_day_boundary(start_date))
    if end_date is not None:
-        query = query.where(MessageFeedback.created_at < datetime.combine(end_date + timedelta(days=1), time.min))
+        query = query.where(MessageFeedback.created_at < business_day_boundary(end_date, end_exclusive=True))
    return query


@@ -159,8 +160,8 @@ def _feedback_workbook(rows: list[tuple]) -> Workbook:
            _excel_safe_text(session.title),
            message.id,
            _excel_safe_text(ensure_ai_generated_notice(message.content)),
-            feedback.created_at,
-            feedback.read_at,
+            to_business_naive(feedback.created_at),
+            to_business_naive(feedback.read_at),
        ])
    header_fill = PatternFill("solid", fgColor="1F6F5F")
    for cell in sheet[1]:
--- a/ai_knowledge_base_v2/apps/backend/app/core/database.py
+++ b/ai_knowledge_base_v2/apps/backend/app/core/database.py
@@ -2,7 +2,7 @@ from __future__ import annotations

 from collections.abc import Generator

-from sqlalchemy import create_engine
+from sqlalchemy import create_engine, event
 from sqlalchemy.orm import Session, sessionmaker

 from app.core.config import get_settings
@@ -20,6 +20,16 @@ if not settings.database_url.startswith("sqlite"):
        pool_recycle=settings.db_pool_recycle,
    )
 engine = create_engine(settings.database_url, **engine_options)
+if engine.dialect.name == "mysql":
+    @event.listens_for(engine, "connect")
+    def _set_mysql_session_timezone(dbapi_connection, _connection_record) -> None:
+        """Keep CURRENT_TIMESTAMP and application-written values on one UTC contract."""
+        cursor = dbapi_connection.cursor()
+        try:
+            cursor.execute("SET time_zone = '+00:00'")
+        finally:
+            cursor.close()
+
 SessionLocal = sessionmaker(bind=engine, autoflush=False, autocommit=False, future=True)
 register_knowledge_cache_invalidation_events()

--- a/ai_knowledge_base_v2/apps/backend/app/core/dependencies.py
+++ b/ai_knowledge_base_v2/apps/backend/app/core/dependencies.py
@@ -126,7 +126,9 @@ def enforce_admin_access(
        else:
            permission = "attention.view" if method == "GET" else "attention.edit"
    elif path.startswith("user-behavior"):
-        permission = "behavior.view"
+        permission = "behavior.export" if path.startswith("user-behavior/export") else "behavior.view"
+    elif path == "chat/export" or (path.startswith("chat/") and path.endswith("/export")) or path.startswith("question-insights/export"):
+        permission = "records.export"
    else:
        permission = "records.view"
    require_permission(admin, permission)
--- a/ai_knowledge_base_v2/apps/backend/app/core/responses.py
+++ b/ai_knowledge_base_v2/apps/backend/app/core/responses.py
@@ -2,10 +2,12 @@ from __future__ import annotations

 from typing import Any

+from app.core.time_utils import normalize_api_datetimes
+

 def api_success(data: Any = None, message: str = "success") -> dict[str, Any]:
-    return {"code": 0, "message": message, "data": data}
+    return {"code": 0, "message": message, "data": normalize_api_datetimes(data)}


 def api_error(code: int, message: str, data: Any = None) -> dict[str, Any]:
-    return {"code": code, "message": message, "data": data}
+    return {"code": code, "message": message, "data": normalize_api_datetimes(data)}
--- a/ai_knowledge_base_v2/apps/backend/app/core/time_utils.py
+++ b/ai_knowledge_base_v2/apps/backend/app/core/time_utils.py
@@ -0,0 +1,64 @@
+from __future__ import annotations
+
+from datetime import UTC, date, datetime, time, timedelta
+from typing import Any
+from zoneinfo import ZoneInfo
+
+
+BUSINESS_TIMEZONE = ZoneInfo("Asia/Shanghai")
+
+
+def utc_now_naive() -> datetime:
+    """Return the database timestamp convention: UTC without tzinfo."""
+    return datetime.now(UTC).replace(tzinfo=None)
+
+
+def as_utc_naive(value: datetime) -> datetime:
+    """Normalize an API datetime to the database UTC-naive convention."""
+    if value.tzinfo is None:
+        return value
+    return value.astimezone(UTC).replace(tzinfo=None)
+
+
+def business_day_boundary(value: date, *, end_exclusive: bool = False) -> datetime:
+    """Convert a Beijing calendar-day boundary to UTC-naive database time."""
+    local_value = datetime.combine(value, time.min, tzinfo=BUSINESS_TIMEZONE)
+    if end_exclusive:
+        local_value += timedelta(days=1)
+    return local_value.astimezone(UTC).replace(tzinfo=None)
+
+
+def business_datetime_to_utc_naive(value: datetime) -> datetime:
+    """Interpret a timezone-free operator input as Beijing local time."""
+    if value.tzinfo is not None:
+        return as_utc_naive(value)
+    return value.replace(tzinfo=BUSINESS_TIMEZONE).astimezone(UTC).replace(tzinfo=None)
+
+
+def to_business_naive(value: datetime | None) -> datetime | None:
+    """Convert UTC database time to a timezone-free Beijing value for Excel."""
+    if value is None:
+        return None
+    aware = value.replace(tzinfo=UTC) if value.tzinfo is None else value.astimezone(UTC)
+    return aware.astimezone(BUSINESS_TIMEZONE).replace(tzinfo=None)
+
+
+def api_datetime(value: datetime) -> str:
+    """Serialize datetimes with an explicit offset; naive values are database UTC."""
+    aware = value.replace(tzinfo=UTC) if value.tzinfo is None else value
+    return aware.astimezone(UTC).isoformat(timespec="milliseconds").replace("+00:00", "Z")
+
+
+def normalize_api_datetimes(value: Any) -> Any:
+    """Recursively enforce the API time contract for ordinary JSON responses."""
+    if isinstance(value, datetime):
+        return api_datetime(value)
+    if isinstance(value, date):
+        return value.isoformat()
+    if isinstance(value, dict):
+        return {key: normalize_api_datetimes(item) for key, item in value.items()}
+    if isinstance(value, list):
+        return [normalize_api_datetimes(item) for item in value]
+    if isinstance(value, tuple):
+        return [normalize_api_datetimes(item) for item in value]
+    return value
--- a/ai_knowledge_base_v2/apps/backend/app/models/knowledge.py
+++ b/ai_knowledge_base_v2/apps/backend/app/models/knowledge.py
@@ -248,6 +248,9 @@ class KnowledgeRetrievalCandidate(Base):

 class HumanAttentionRecord(Base):
    __tablename__ = "sys_human_attention_record"
+    __table_args__ = (
+        Index("ix_human_attention_created", "created_at", "id"),
+    )

    id: Mapped[int] = mapped_column(PRIMARY_KEY_TYPE, primary_key=True, autoincrement=True)
    session_id: Mapped[int] = mapped_column(BigInteger, index=True, nullable=False)
--- a/ai_knowledge_base_v2/apps/backend/app/services/admin_permission_service.py
+++ b/ai_knowledge_base_v2/apps/backend/app/services/admin_permission_service.py
@@ -17,11 +17,11 @@ PERMISSION_TREE = [
    {"code": "content-generation", "name": "内容生成", "children": [{"code": "content-generation.view", "name": "查看配置"}, {"code": "content-generation.edit", "name": "编辑/测试配置"}]},
    {"code": "configs", "name": "系统配置", "children": [{"code": "configs.view", "name": "查看配置"}, {"code": "configs.edit", "name": "修改配置"}]},
    {"code": "sso", "name": "应用接入", "children": [{"code": "sso.view", "name": "查看应用"}, {"code": "sso.edit", "name": "管理应用"}]},
-    {"code": "records", "name": "记录审计", "children": [{"code": "records.view", "name": "查看/导出记录"}]},
+    {"code": "records", "name": "记录审计", "children": [{"code": "records.view", "name": "查看记录"}, {"code": "records.export", "name": "导出记录/洞察"}]},
    {"code": "retrievals", "name": "检索日志", "children": [{"code": "retrievals.view", "name": "查看检索日志"}]},
    {"code": "attention", "name": "人工关注", "children": [{"code": "attention.view", "name": "查看关注项"}, {"code": "attention.edit", "name": "处理/删除关注项"}, {"code": "attention.config", "name": "查看/修改筛选规则"}, {"code": "attention.preview", "name": "使用历史消息预览筛选效果"}]},
    {"code": "feedback", "name": "反馈管理", "children": [{"code": "feedback.view", "name": "查看反馈列表/筛选分页"}, {"code": "feedback.detail", "name": "查看详情/标记已读"}, {"code": "feedback.export", "name": "导出反馈"}, {"code": "feedback.delete", "name": "删除反馈"}]},
-    {"code": "behavior", "name": "用户行为分析", "children": [{"code": "behavior.view", "name": "查看行为总览和用户轨迹"}]},
+    {"code": "behavior", "name": "用户行为分析", "children": [{"code": "behavior.view", "name": "查看行为总览和用户轨迹"}, {"code": "behavior.export", "name": "导出用户行为报表"}]},
    {"code": "admins", "name": "管理员与权限", "superOnly": True, "children": [{"code": "admins.view", "name": "查看管理员"}, {"code": "admins.edit", "name": "新增/编辑管理员"}, {"code": "admins.delete", "name": "删除管理员"}]},
 ]

--- a/ai_knowledge_base_v2/apps/backend/app/services/admin_service.py
+++ b/ai_knowledge_base_v2/apps/backend/app/services/admin_service.py
@@ -141,10 +141,10 @@ class AdminDashboardService:
            msg_filter.append(ChatMessage.created_at >= start)
            ai_filter.append(AiRequestLog.created_at >= start)
        if end:
-            user_filter.append(User.created_at <= end)
-            session_filter.append(ChatSession.created_at <= end)
-            msg_filter.append(ChatMessage.created_at <= end)
-            ai_filter.append(AiRequestLog.created_at <= end)
+            user_filter.append(User.created_at < end)
+            session_filter.append(ChatSession.created_at < end)
+            msg_filter.append(ChatMessage.created_at < end)
+            ai_filter.append(AiRequestLog.created_at < end)

        user_where = and_(true(), *user_filter)
        session_where = and_(true(), *session_filter)
--- a/ai_knowledge_base_v2/apps/backend/app/services/chat_export_service.py
+++ b/ai_knowledge_base_v2/apps/backend/app/services/chat_export_service.py
@@ -0,0 +1,131 @@
+from __future__ import annotations
+
+from collections.abc import Iterable
+from io import BytesIO
+
+from openpyxl import Workbook
+from openpyxl.styles import Alignment, Font, PatternFill
+from openpyxl.worksheet.table import Table, TableStyleInfo
+
+from app.core.ai_content_label import ensure_ai_generated_notice
+from app.core.time_utils import to_business_naive
+from app.models.chat import ChatMessage, ChatSession
+from app.models.user import User
+
+
+class ChatExportService:
+    """Build a complete, pagination-independent workbook for one chat session."""
+
+    @staticmethod
+    def build(
+        *,
+        session: ChatSession,
+        user: User | None,
+        source_name: str,
+        messages: Iterable[ChatMessage],
+    ) -> BytesIO:
+        message_rows = list(messages)
+        workbook = Workbook()
+        info_sheet = workbook.active
+        info_sheet.title = "会话信息"
+        _write_session_info(
+            info_sheet,
+            session=session,
+            user=user,
+            source_name=source_name,
+            message_count=len(message_rows),
+        )
+
+        message_sheet = workbook.create_sheet("完整对话")
+        _write_messages(message_sheet, message_rows)
+
+        stream = BytesIO()
+        workbook.save(stream)
+        stream.seek(0)
+        return stream
+
+
+def _write_session_info(
+    sheet,
+    *,
+    session: ChatSession,
+    user: User | None,
+    source_name: str,
+    message_count: int,
+) -> None:
+    sheet.sheet_view.showGridLines = False
+    sheet.append(["项目", "内容"])
+    rows = [
+        ("会话ID", session.id),
+        ("会话标题", _excel_safe(session.title)),
+        ("用户ID", session.user_id),
+        ("用户姓名", _excel_safe(user.name if user else "")),
+        ("手机号", _excel_safe(user.phone if user else "")),
+        ("会话来源", _excel_safe(source_name)),
+        ("消息总数", message_count),
+        ("最后消息时间", to_business_naive(session.last_message_at)),
+        ("会话更新时间", to_business_naive(session.updated_at)),
+    ]
+    for label, value in rows:
+        sheet.append([label, value])
+    _style_header(sheet[1])
+    sheet.freeze_panes = "A2"
+    sheet.column_dimensions["A"].width = 20
+    sheet.column_dimensions["B"].width = 72
+    for row in sheet.iter_rows(min_row=2):
+        row[0].font = Font(bold=True, color="31584F")
+        row[1].alignment = Alignment(vertical="top", wrap_text=True)
+    for row_number in (9, 10):
+        sheet.cell(row_number, 2).number_format = "yyyy-mm-dd hh:mm:ss"
+
+
+def _write_messages(sheet, messages: Iterable[ChatMessage]) -> None:
+    headers = ["序号", "消息ID", "发送方", "发送时间", "消息内容", "状态", "输入Token", "输出Token", "耗时(ms)"]
+    sheet.append(headers)
+    count = 0
+    for count, message in enumerate(messages, start=1):
+        content = ensure_ai_generated_notice(message.content) if message.role == "assistant" else message.content
+        sheet.append(
+            [
+                count,
+                message.id,
+                "用户" if message.role == "user" else "大本营答疑助手",
+                to_business_naive(message.created_at),
+                _excel_safe(content),
+                message.message_status,
+                message.token_input,
+                message.token_output,
+                message.response_time_ms,
+            ]
+        )
+    _style_header(sheet[1])
+    sheet.freeze_panes = "A2"
+    sheet.auto_filter.ref = f"A1:I{max(1, sheet.max_row)}"
+    widths = (8, 12, 20, 22, 88, 14, 14, 14, 14)
+    for index, width in enumerate(widths, start=1):
+        sheet.column_dimensions[chr(64 + index)].width = width
+    for row in sheet.iter_rows(min_row=2):
+        row[3].number_format = "yyyy-mm-dd hh:mm:ss"
+        row[4].alignment = Alignment(vertical="top", wrap_text=True)
+    if count:
+        table = Table(displayName="ChatMessages", ref=f"A1:I{sheet.max_row}")
+        table.tableStyleInfo = TableStyleInfo(
+            name="TableStyleMedium4",
+            showFirstColumn=False,
+            showLastColumn=False,
+            showRowStripes=True,
+        )
+        sheet.add_table(table)
+
+
+def _style_header(cells) -> None:
+    fill = PatternFill("solid", fgColor="176B57")
+    for cell in cells:
+        cell.fill = fill
+        cell.font = Font(color="FFFFFF", bold=True)
+        cell.alignment = Alignment(horizontal="center", vertical="center")
+
+
+def _excel_safe(value: object | None) -> str:
+    text = str(value or "")
+    return f"'{text}" if text.lstrip().startswith(("=", "+", "-", "@")) else text
--- a/ai_knowledge_base_v2/apps/backend/app/services/entitlement_service.py
+++ b/ai_knowledge_base_v2/apps/backend/app/services/entitlement_service.py
@@ -11,6 +11,7 @@ from sqlalchemy.orm import Session

 from app.models.entitlement import EntitlementPlan, UserEntitlement, UserEntitlementLog
 from app.models.user import User
+from app.core.time_utils import as_utc_naive


 DEFAULT_PLAN_TYPE = "basic"
@@ -260,12 +261,12 @@ class EntitlementService:
            raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="权益版本不存在或已停用")
        now = _now()
        if effective_at is not None:
-            effective_at = effective_at.replace(tzinfo=None)
+            effective_at = as_utc_naive(effective_at)
        if expired_at is None and plan.validity_days:
            start = effective_at or now
            expired_at = start + timedelta(days=plan.validity_days)
        elif expired_at is not None:
-            expired_at = expired_at.replace(tzinfo=None)
+            expired_at = as_utc_naive(expired_at)
        if expired_at is not None and effective_at is not None and expired_at < effective_at:
            raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail="权益到期时间不能早于生效时间")

--- a/ai_knowledge_base_v2/apps/backend/app/services/maintenance_service.py
+++ b/ai_knowledge_base_v2/apps/backend/app/services/maintenance_service.py
@@ -13,6 +13,7 @@ from app.services.redis_client import get_sync_redis_client
 from app.services.entitlement_service import EntitlementService
 from app.services.user_behavior_service import UserBehaviorService
 from app.core.config import get_settings
+from app.core.time_utils import utc_now_naive


 class MaintenanceService:
@@ -43,11 +44,12 @@ class MaintenanceService:
                policy = db.scalar(select(LogRetentionPolicy).order_by(LogRetentionPolicy.id).limit(1))
                if not policy or not policy.enabled or not policy.retention_days:
                    return
-                if policy.last_run_at and policy.last_run_at.date() >= datetime.now().date():
+                now = utc_now_naive()
+                if policy.last_run_at and policy.last_run_at.date() >= now.date():
                    return
-                before = datetime.now() - timedelta(days=policy.retention_days)
+                before = now - timedelta(days=policy.retention_days)
                deleted = cls.delete_retrieval_logs(db, before)
-                policy.last_run_at = datetime.now()
+                policy.last_run_at = now
                policy.last_result = json.dumps({"status": "success", "deleted": deleted, "before": before.isoformat()}, ensure_ascii=False)
                db.add(policy)
                db.commit()
@@ -55,7 +57,7 @@ class MaintenanceService:
            with SessionLocal() as db:
                policy = db.scalar(select(LogRetentionPolicy).order_by(LogRetentionPolicy.id).limit(1))
                if policy:
-                    policy.last_run_at = datetime.now()
+                    policy.last_run_at = utc_now_naive()
                    policy.last_result = json.dumps({"status": "failed", "error": str(exc)[:1000]}, ensure_ascii=False)
                    db.add(policy)
                    db.commit()
--- a/ai_knowledge_base_v2/apps/backend/app/services/periodic_report_service.py
+++ b/ai_knowledge_base_v2/apps/backend/app/services/periodic_report_service.py
@@ -629,4 +629,4 @@ def _local_datetime(value: datetime) -> datetime:
    except ZoneInfoNotFoundError:
        timezone = ZoneInfo("Asia/Shanghai")
    aware_utc = value.replace(tzinfo=UTC) if value.tzinfo is None else value.astimezone(UTC)
-    return aware_utc.astimezone(timezone).replace(tzinfo=None)
+    return aware_utc.astimezone(timezone)
--- a/ai_knowledge_base_v2/apps/backend/app/services/question_insight_export_service.py
+++ b/ai_knowledge_base_v2/apps/backend/app/services/question_insight_export_service.py
@@ -8,6 +8,7 @@ from openpyxl.styles import Alignment, Font, PatternFill
 from openpyxl.worksheet.table import Table, TableStyleInfo

 from app.core.ai_content_label import AI_GENERATED_NOTICE
+from app.core.time_utils import to_business_naive, utc_now_naive


 class QuestionInsightExportService:
@@ -116,7 +117,7 @@ def _append_summary(sheet, result: dict) -> None:
        ("导出问题组", summary.get("visibleClusterCount", 0)),
        ("清洗规则版本", summary.get("cleanerVersion", "")),
        ("内容标识", AI_GENERATED_NOTICE),
-        ("导出时间", datetime.now()),
+        ("导出时间", to_business_naive(utc_now_naive())),
        ("说明", "导出结果按所选日期范围和最低频次生成，包含全部符合条件的问题组，不受页面分页影响。"),
    ]
    for label, value in rows:
@@ -165,6 +166,6 @@ def _excel_safe(value: object | None) -> str:


 def _excel_datetime(value: object) -> object:
-    if isinstance(value, datetime) and value.tzinfo is not None:
-        return value.replace(tzinfo=None)
+    if isinstance(value, datetime):
+        return to_business_naive(value)
    return value
--- a/ai_knowledge_base_v2/apps/backend/app/services/question_insight_service.py
+++ b/ai_knowledge_base_v2/apps/backend/app/services/question_insight_service.py
@@ -17,6 +17,7 @@ from app.models.chat import ChatMessage, ChatSession
 from app.models.insight import QuestionInsightCleanedQuestion
 from app.models.logs import AiRequestLog
 from app.models.user import User
+from app.core.time_utils import as_utc_naive


 CLEANER_VERSION = "v1"
@@ -249,9 +250,9 @@ def _load_unprocessed_user_messages(
        )
    )
    if date_from is not None:
-        query = query.where(ChatMessage.created_at >= date_from.replace(tzinfo=None))
+        query = query.where(ChatMessage.created_at >= as_utc_naive(date_from))
    if date_to is not None:
-        query = query.where(ChatMessage.created_at <= date_to.replace(tzinfo=None))
+        query = query.where(ChatMessage.created_at <= as_utc_naive(date_to))
    return list(
        db.execute(
            query.order_by(ChatMessage.created_at.desc(), ChatMessage.id.desc()).limit(limit)
@@ -268,9 +269,9 @@ def _load_persisted_cleaned_questions(
 ) -> list[QuestionInsightCleanedQuestion]:
    range_filters = [QuestionInsightCleanedQuestion.cleaner_version == CLEANER_VERSION]
    if date_from is not None:
-        range_filters.append(QuestionInsightCleanedQuestion.source_created_at >= date_from.replace(tzinfo=None))
+        range_filters.append(QuestionInsightCleanedQuestion.source_created_at >= as_utc_naive(date_from))
    if date_to is not None:
-        range_filters.append(QuestionInsightCleanedQuestion.source_created_at <= date_to.replace(tzinfo=None))
+        range_filters.append(QuestionInsightCleanedQuestion.source_created_at <= as_utc_naive(date_to))

    latest_messages = (
        select(
@@ -312,9 +313,9 @@ def _load_ai_logs(
 ) -> list[AiRequestLog]:
    query = select(AiRequestLog)
    if date_from is not None:
-        query = query.where(AiRequestLog.created_at >= date_from.replace(tzinfo=None))
+        query = query.where(AiRequestLog.created_at >= as_utc_naive(date_from))
    if date_to is not None:
-        query = query.where(AiRequestLog.created_at <= date_to.replace(tzinfo=None))
+        query = query.where(AiRequestLog.created_at <= as_utc_naive(date_to))
    return list(db.scalars(query.order_by(AiRequestLog.created_at.desc(), AiRequestLog.id.desc()).limit(limit)).all())


--- a/ai_knowledge_base_v2/apps/backend/app/services/user_behavior_export_service.py
+++ b/ai_knowledge_base_v2/apps/backend/app/services/user_behavior_export_service.py
@@ -0,0 +1,203 @@
+from __future__ import annotations
+
+from datetime import date, datetime
+from io import BytesIO
+from copy import copy
+
+from openpyxl import Workbook
+from openpyxl.styles import Alignment, Font, PatternFill
+from openpyxl.utils import get_column_letter
+from sqlalchemy.orm import Session
+
+from app.services.user_behavior_service import EVENT_CATALOG, UserBehaviorService
+from app.core.time_utils import to_business_naive, utc_now_naive
+
+
+TITLE_FILL = PatternFill("solid", fgColor="176B55")
+HEADER_FILL = PatternFill("solid", fgColor="DDEFE9")
+TITLE_FONT = Font(color="FFFFFF", bold=True, size=16)
+HEADER_FONT = Font(color="214239", bold=True)
+EVENT_TYPE_LABELS = {"page": "页面", "dialog": "弹窗", "button": "按钮"}
+SORT_LABELS = {
+    "userName": "用户名称",
+    "phone": "手机号",
+    "eventCount": "交互次数",
+    "lastEventAt": "最后交互时间",
+}
+FONT_NAME = "Hiragino Sans GB"
+
+
+class UserBehaviorExportService:
+    @staticmethod
+    def build_workbook(
+        db: Session,
+        *,
+        start: date | None,
+        end: date | None,
+        keyword: str,
+        sort_by: str,
+        sort_order: str,
+    ) -> BytesIO:
+        overview = UserBehaviorService.overview(
+            db,
+            start=start,
+            end=end,
+            ranking_limit=len(EVENT_CATALOG),
+        )
+        users = UserBehaviorService.users_for_export(
+            db,
+            start=start,
+            end=end,
+            keyword=keyword,
+            sort_by=sort_by,
+            sort_order=sort_order,
+        )
+        workbook = Workbook()
+        summary = workbook.active
+        summary.title = "报表说明"
+        _write_summary(summary, overview, keyword=keyword, sort_by=sort_by, sort_order=sort_order)
+        _write_daily(workbook.create_sheet("每日趋势"), overview["daily"])
+        _write_ranking(workbook.create_sheet("功能使用频率"), overview["eventRanking"])
+        _write_users(workbook.create_sheet("用户汇总"), users)
+        stream = BytesIO()
+        workbook.save(stream)
+        stream.seek(0)
+        return stream
+
+
+def _write_summary(sheet, overview: dict, *, keyword: str, sort_by: str, sort_order: str) -> None:
+    sheet.sheet_view.showGridLines = False
+    sheet.merge_cells("A1:D1")
+    title = sheet["A1"]
+    title.value = "用户行为分析报表"
+    title.fill = TITLE_FILL
+    title.font = TITLE_FONT
+    title.alignment = Alignment(horizontal="center", vertical="center")
+    sheet.row_dimensions[1].height = 30
+    metadata = [
+        ("统计周期", f'{overview["startDate"]} 至 {overview["endDate"]}'),
+        ("用户筛选", _excel_safe(keyword.strip()) if keyword.strip() else "全部用户"),
+        ("用户汇总排序", f'{SORT_LABELS[sort_by]}·{"升序" if sort_order == "asc" else "降序"}'),
+        ("数据保留", f'{overview["retentionDays"]} 天'),
+        ("导出时间", to_business_naive(utc_now_naive())),
+    ]
+    for row_index, (label, value) in enumerate(metadata, start=3):
+        sheet.cell(row_index, 1, label).font = HEADER_FONT
+        sheet.cell(row_index, 2, value)
+    metrics = [
+        ("交互事件", overview["totalEvents"]),
+        ("活跃用户", overview["activeUsers"]),
+        ("页面/弹窗打开", overview["pageDialogOpens"]),
+        ("关键按钮点击", overview["buttonClicks"]),
+    ]
+    sheet.cell(10, 1, "核心指标").fill = HEADER_FILL
+    sheet.cell(10, 1).font = HEADER_FONT
+    sheet.cell(10, 2, "数值").fill = HEADER_FILL
+    sheet.cell(10, 2).font = HEADER_FONT
+    for row_index, (label, value) in enumerate(metrics, start=11):
+        sheet.cell(row_index, 1, label)
+        sheet.cell(row_index, 2, value).number_format = "#,##0"
+    sheet.column_dimensions["A"].width = 22
+    sheet.column_dimensions["B"].width = 34
+    sheet.column_dimensions["C"].width = 16
+    sheet.column_dimensions["D"].width = 16
+    sheet["B7"].number_format = "yyyy-mm-dd hh:mm:ss"
+    _finish_sheet(sheet, landscape=True)
+
+
+def _write_daily(sheet, rows: list[dict]) -> None:
+    _write_tabular_sheet(sheet, ["日期", "交互事件", "活跃用户"])
+    for item in rows:
+        sheet.append([date.fromisoformat(item["date"]), item["eventCount"], item["activeUsers"]])
+    for cell in sheet["A"][1:]:
+        cell.number_format = "yyyy-mm-dd"
+    for column in ("B", "C"):
+        for cell in sheet[column][1:]:
+            cell.number_format = "#,##0"
+    _finish_tabular_sheet(sheet, widths=(15, 15, 15))
+
+
+def _write_ranking(sheet, rows: list[dict]) -> None:
+    _write_tabular_sheet(sheet, ["排名", "功能名称", "事件类型", "使用次数", "用户数", "事件代码"])
+    for index, item in enumerate(rows, start=1):
+        sheet.append(
+            [
+                index,
+                _excel_safe(item["eventName"]),
+                EVENT_TYPE_LABELS.get(item["eventType"], item["eventType"]),
+                item["count"],
+                item["userCount"],
+                item["eventCode"],
+            ]
+        )
+    for column in ("A", "D", "E"):
+        for cell in sheet[column][1:]:
+            cell.number_format = "#,##0"
+    _finish_tabular_sheet(sheet, widths=(10, 24, 14, 14, 14, 30))
+
+
+def _write_users(sheet, rows: list[dict]) -> None:
+    _write_tabular_sheet(sheet, ["用户ID", "用户", "手机号", "交互次数", "最后交互时间"])
+    for item in rows:
+        sheet.append(
+            [
+                item["userId"],
+                _excel_safe(item["userName"]),
+                _excel_safe(item["phone"]),
+                item["eventCount"],
+                to_business_naive(item["lastEventAt"]),
+            ]
+        )
+    for cell in sheet["A"][1:]:
+        cell.number_format = "0"
+    for cell in sheet["C"][1:]:
+        cell.number_format = "@"
+    for cell in sheet["D"][1:]:
+        cell.number_format = "#,##0"
+    for cell in sheet["E"][1:]:
+        cell.number_format = "yyyy-mm-dd hh:mm:ss"
+    _finish_tabular_sheet(sheet, widths=(12, 22, 18, 14, 22))
+
+
+def _write_tabular_sheet(sheet, headers: list[str]) -> None:
+    sheet.sheet_view.showGridLines = False
+    sheet.append(headers)
+    for cell in sheet[1]:
+        cell.fill = HEADER_FILL
+        cell.font = HEADER_FONT
+        cell.alignment = Alignment(horizontal="center", vertical="center")
+    sheet.row_dimensions[1].height = 24
+    sheet.freeze_panes = "A2"
+
+
+def _finish_tabular_sheet(sheet, *, widths: tuple[int, ...]) -> None:
+    sheet.auto_filter.ref = sheet.dimensions
+    for index, width in enumerate(widths, start=1):
+        sheet.column_dimensions[get_column_letter(index)].width = width
+    for row in sheet.iter_rows(min_row=2):
+        for cell in row:
+            cell.alignment = Alignment(vertical="top", wrap_text=True)
+    _finish_sheet(sheet, landscape=True)
+
+
+def _finish_sheet(sheet, *, landscape: bool) -> None:
+    for row in sheet.iter_rows():
+        for cell in row:
+            font = copy(cell.font)
+            font.name = FONT_NAME
+            cell.font = font
+    sheet.sheet_properties.pageSetUpPr.fitToPage = True
+    sheet.page_setup.fitToWidth = 1
+    sheet.page_setup.fitToHeight = 0
+    sheet.page_setup.orientation = "landscape" if landscape else "portrait"
+    sheet.page_setup.paperSize = sheet.PAPERSIZE_A4
+    sheet.page_margins.left = 0.3
+    sheet.page_margins.right = 0.3
+    sheet.page_margins.top = 0.5
+    sheet.page_margins.bottom = 0.5
+    sheet.print_area = sheet.dimensions
+
+
+def _excel_safe(value: object) -> str:
+    text = "" if value is None else str(value)
+    return f"'{text}" if text.startswith(("=", "+", "-", "@")) else text
--- a/ai_knowledge_base_v2/apps/backend/app/services/user_behavior_service.py
+++ b/ai_knowledge_base_v2/apps/backend/app/services/user_behavior_service.py
@@ -1,7 +1,6 @@
 from __future__ import annotations

-from datetime import UTC, date, datetime, time, timedelta
-from zoneinfo import ZoneInfo
+from datetime import UTC, date, datetime, timedelta

 from sqlalchemy import case, delete, func, or_, select
 from sqlalchemy.exc import IntegrityError
@@ -11,6 +10,7 @@ from app.models.behavior import UserBehaviorEvent
 from app.models.user import User
 from app.schemas.behavior import UserBehaviorEventCreate
 from app.core.config import get_settings
+from app.core.time_utils import BUSINESS_TIMEZONE, business_day_boundary, to_business_naive


 EVENT_CATALOG: dict[str, tuple[str, str]] = {
@@ -48,6 +48,8 @@ EVENT_CATALOG: dict[str, tuple[str, str]] = {
 TARGET_TYPES = {"session", "message", "help_card", "share_draft", "report"}
 DEFAULT_RANGE_DAYS = 7
 MAX_RANGE_DAYS = 31
+USER_SORT_FIELDS = {"userName", "phone", "eventCount", "lastEventAt"}
+USER_SORT_ORDERS = {"asc", "desc"}


 class UserBehaviorService:
@@ -97,7 +99,7 @@ class UserBehaviorService:
        return accepted

    @staticmethod
-    def overview(db: Session, *, start: date | None, end: date | None) -> dict:
+    def overview(db: Session, *, start: date | None, end: date | None, ranking_limit: int = 20) -> dict:
        start_dt, end_dt = _date_range(start, end)
        base = (UserBehaviorEvent.occurred_at >= start_dt, UserBehaviorEvent.occurred_at < end_dt)
        total, active_users, page_opens, button_clicks = db.execute(
@@ -119,7 +121,7 @@ class UserBehaviorService:
            .where(*base)
            .group_by(UserBehaviorEvent.event_code, UserBehaviorEvent.event_name, UserBehaviorEvent.event_type)
            .order_by(func.count(UserBehaviorEvent.id).desc(), UserBehaviorEvent.event_code)
-            .limit(20)
+            .limit(max(1, min(ranking_limit, len(EVENT_CATALOG))))
        ).all()
        if db.bind and db.bind.dialect.name == "mysql":
            day_expression = func.date(func.convert_tz(UserBehaviorEvent.occurred_at, "+00:00", "+08:00"))
@@ -135,8 +137,8 @@ class UserBehaviorService:
            .group_by(day_expression)
            .order_by(day_expression)
        ).all()
-        local_start = (start_dt + timedelta(hours=8)).date()
-        local_end = (end_dt + timedelta(hours=8) - timedelta(days=1)).date()
+        local_start = to_business_naive(start_dt).date()
+        local_end = (to_business_naive(end_dt) - timedelta(days=1)).date()
        daily_map = {str(day): (event_count, users) for day, event_count, users in daily_rows}
        daily = []
        cursor = local_start
@@ -160,47 +162,57 @@ class UserBehaviorService:
        }

    @staticmethod
-    def users(db: Session, *, start: date | None, end: date | None, keyword: str, page: int, page_size: int) -> dict:
-        start_dt, end_dt = _date_range(start, end)
-        filters = [UserBehaviorEvent.occurred_at >= start_dt, UserBehaviorEvent.occurred_at < end_dt]
-        if keyword.strip():
-            pattern = f"%{keyword.strip()}%"
-            filters.append(or_(User.name.like(pattern), User.nickname.like(pattern), User.phone.like(pattern)))
-        grouped = (
-            select(
-                User.id.label("user_id"),
-                User.name,
-                User.nickname,
-                User.phone,
-                func.count(UserBehaviorEvent.id).label("event_count"),
-                func.max(UserBehaviorEvent.occurred_at).label("last_event_at"),
-            )
-            .join(UserBehaviorEvent, UserBehaviorEvent.user_id == User.id)
-            .where(*filters)
-            .group_by(User.id, User.name, User.nickname, User.phone)
+    def users(
+        db: Session,
+        *,
+        start: date | None,
+        end: date | None,
+        keyword: str,
+        page: int,
+        page_size: int,
+        sort_by: str = "lastEventAt",
+        sort_order: str = "desc",
+    ) -> dict:
+        grouped, order_expression = _user_summary_query(
+            start=start,
+            end=end,
+            keyword=keyword,
+            sort_by=sort_by,
+            sort_order=sort_order,
        )
        total = db.scalar(select(func.count()).select_from(grouped.subquery())) or 0
        rows = db.execute(
-            grouped.order_by(func.max(UserBehaviorEvent.occurred_at).desc(), User.id.desc())
+            grouped.order_by(order_expression, User.id.asc())
            .offset((page - 1) * page_size)
            .limit(page_size)
        ).all()
        return {
-            "items": [
-                {
-                    "userId": row.user_id,
-                    "userName": row.nickname or row.name,
-                    "phone": row.phone,
-                    "eventCount": row.event_count,
-                    "lastEventAt": row.last_event_at,
-                }
-                for row in rows
-            ],
+            "items": [_user_summary_dict(row) for row in rows],
            "total": total,
            "page": page,
            "pageSize": page_size,
        }

+    @staticmethod
+    def users_for_export(
+        db: Session,
+        *,
+        start: date | None,
+        end: date | None,
+        keyword: str,
+        sort_by: str,
+        sort_order: str,
+    ) -> list[dict]:
+        grouped, order_expression = _user_summary_query(
+            start=start,
+            end=end,
+            keyword=keyword,
+            sort_by=sort_by,
+            sort_order=sort_order,
+        )
+        rows = db.execute(grouped.order_by(order_expression, User.id.asc())).all()
+        return [_user_summary_dict(row) for row in rows]
+
    @staticmethod
    def timeline(db: Session, *, user_id: int, start: date | None, end: date | None, page: int, page_size: int) -> dict:
        user = db.get(User, user_id)
@@ -249,18 +261,67 @@ class UserBehaviorService:


 def _date_range(start: date | None, end: date | None) -> tuple[datetime, datetime]:
-    today = datetime.now(ZoneInfo("Asia/Shanghai")).date()
+    today = datetime.now(BUSINESS_TIMEZONE).date()
    end_date = end or today
    start_date = start or (end_date - timedelta(days=DEFAULT_RANGE_DAYS - 1))
    if end_date < start_date:
        start_date, end_date = end_date, start_date
    if (end_date - start_date).days >= MAX_RANGE_DAYS:
        start_date = end_date - timedelta(days=MAX_RANGE_DAYS - 1)
-    # Admin date filters are Beijing calendar days; persisted timestamps are UTC-naive.
-    return (
-        datetime.combine(start_date, time.min) - timedelta(hours=8),
-        datetime.combine(end_date + timedelta(days=1), time.min) - timedelta(hours=8),
+    return business_day_boundary(start_date), business_day_boundary(end_date, end_exclusive=True)
+
+
+def _user_summary_query(
+    *,
+    start: date | None,
+    end: date | None,
+    keyword: str,
+    sort_by: str,
+    sort_order: str,
+):
+    if sort_by not in USER_SORT_FIELDS:
+        raise ValueError(f"unsupported user behavior sort field: {sort_by}")
+    if sort_order not in USER_SORT_ORDERS:
+        raise ValueError(f"unsupported user behavior sort order: {sort_order}")
+    start_dt, end_dt = _date_range(start, end)
+    filters = [UserBehaviorEvent.occurred_at >= start_dt, UserBehaviorEvent.occurred_at < end_dt]
+    if keyword.strip():
+        pattern = f"%{keyword.strip()}%"
+        filters.append(or_(User.name.like(pattern), User.nickname.like(pattern), User.phone.like(pattern)))
+    user_name = func.coalesce(func.nullif(User.nickname, ""), User.name)
+    event_count = func.count(UserBehaviorEvent.id)
+    last_event_at = func.max(UserBehaviorEvent.occurred_at)
+    grouped = (
+        select(
+            User.id.label("user_id"),
+            User.name,
+            User.nickname,
+            User.phone,
+            event_count.label("event_count"),
+            last_event_at.label("last_event_at"),
+        )
+        .join(UserBehaviorEvent, UserBehaviorEvent.user_id == User.id)
+        .where(*filters)
+        .group_by(User.id, User.name, User.nickname, User.phone)
    )
+    sort_expressions = {
+        "userName": user_name,
+        "phone": User.phone,
+        "eventCount": event_count,
+        "lastEventAt": last_event_at,
+    }
+    expression = sort_expressions[sort_by]
+    return grouped, expression.asc() if sort_order == "asc" else expression.desc()
+
+
+def _user_summary_dict(row) -> dict:
+    return {
+        "userId": row.user_id,
+        "userName": row.nickname or row.name,
+        "phone": row.phone,
+        "eventCount": row.event_count,
+        "lastEventAt": row.last_event_at,
+    }


 def _event_dict(item: UserBehaviorEvent) -> dict:
--- a/ai_knowledge_base_v2/apps/backend/tests/test_admin_pagination.py
+++ b/ai_knowledge_base_v2/apps/backend/tests/test_admin_pagination.py
@@ -101,7 +101,14 @@ def test_chat_detail_messages_are_paginated():
        ])
        db.commit()

-        response = chat_detail(1, messagePage=2, messagePageSize=10, db=db, current_admin=object())
+        response = chat_detail(
+            1,
+            messagePage=2,
+            messagePageSize=10,
+            focusMessageId=None,
+            db=db,
+            current_admin=object(),
+        )

        data = response["data"]
        assert data["session"]["messageCount"] == 25
@@ -111,6 +118,40 @@ def test_chat_detail_messages_are_paginated():
        assert data["messages"][0]["content"] == "消息11"


+def test_chat_detail_focus_message_opens_its_page_in_chronological_order():
+    with _database() as db:
+        user = User(id=1, phone="13800000000", name="学员", daily_chat_limit=10)
+        session = ChatSession(id=1, user_id=1, title="长会话", message_count=25)
+        created_at = datetime(2026, 8, 25, 10, 0, 0)
+        db.add_all([user, session])
+        db.add_all([
+            ChatMessage(
+                id=index + 1,
+                session_id=1,
+                user_id=1,
+                role="user",
+                content=f"消息{index + 1}",
+                created_at=created_at,
+            )
+            for index in range(25)
+        ])
+        db.commit()
+
+        response = chat_detail(
+            1,
+            messagePage=1,
+            messagePageSize=10,
+            focusMessageId=23,
+            db=db,
+            current_admin=object(),
+        )
+
+        data = response["data"]
+        assert data["messagesPage"]["page"] == 3
+        assert data["focusedMessageId"] == 23
+        assert [item["id"] for item in data["messages"]] == [21, 22, 23, 24, 25]
+
+
 def test_chat_messages_endpoint_returns_only_message_page():
    with _database() as db:
        user = User(id=1, phone="13800000000", name="学员", daily_chat_limit=10)
@@ -149,11 +190,75 @@ def test_retrieval_and_attention_lists_are_paginated():
            sessionId=None, knowledgeId=None, knowledgeCalled=None, statusValue="", attentionCreated=None,
            page=3, pageSize=10, db=db, current_admin=object(),
        )["data"]
-        attention = attention_list(priority="", statusValue="", page=3, pageSize=10, db=db, current_admin=object())["data"]
+        attention = attention_list(
+            priority="",
+            statusValue="",
+            dateFrom=None,
+            dateTo=None,
+            page=3,
+            pageSize=10,
+            db=db,
+            current_admin=object(),
+        )["data"]
        assert retrieval["total"] == attention["total"] == 21
        assert len(retrieval["items"]) == len(attention["items"]) == 1


+def test_attention_list_filters_by_priority_and_trigger_time():
+    with _database() as db:
+        db.add_all([
+            HumanAttentionRecord(
+                session_id=1,
+                message_id=1,
+                user_id=1,
+                trigger_message="紧急问题",
+                problem_summary="紧急问题",
+                trigger_reason="测试",
+                priority="urgent",
+                status="pending",
+                created_at=datetime(2026, 8, 20, 9, 0, 0),
+            ),
+            HumanAttentionRecord(
+                session_id=2,
+                message_id=2,
+                user_id=2,
+                trigger_message="普通问题",
+                problem_summary="普通问题",
+                trigger_reason="测试",
+                priority="normal",
+                status="pending",
+                created_at=datetime(2026, 8, 21, 9, 0, 0),
+            ),
+            HumanAttentionRecord(
+                session_id=3,
+                message_id=3,
+                user_id=3,
+                trigger_message="过期紧急问题",
+                problem_summary="过期紧急问题",
+                trigger_reason="测试",
+                priority="urgent",
+                status="pending",
+                created_at=datetime(2026, 8, 10, 9, 0, 0),
+            ),
+        ])
+        db.commit()
+
+        data = attention_list(
+            priority="urgent",
+            statusValue="",
+            dateFrom=datetime(2026, 8, 20, 0, 0, 0),
+            dateTo=datetime(2026, 8, 22, 23, 59, 59),
+            page=1,
+            pageSize=10,
+            db=db,
+            current_admin=object(),
+        )["data"]
+
+        assert data["total"] == 1
+        assert data["items"][0]["messageId"] == 1
+        assert data["items"][0]["targetAvailable"] is False
+
+
 def test_question_insights_clean_and_cluster_similar_user_questions():
    with _database() as db:
        user_a = User(id=1, phone="13800000000", name="学员A", daily_chat_limit=10)
--- a/ai_knowledge_base_v2/apps/backend/tests/test_admin_permissions.py
+++ b/ai_knowledge_base_v2/apps/backend/tests/test_admin_permissions.py
@@ -16,8 +16,9 @@ def test_super_admin_has_all_permissions() -> None:
    assert permissions_for(admin) == ALL_PERMISSION_CODES
    assert {"feedback.view", "feedback.detail", "feedback.export", "feedback.delete"} <= ALL_PERMISSION_CODES
    assert "prompt.batch" in ALL_PERMISSION_CODES
-    assert "behavior.view" in ALL_PERMISSION_CODES
+    assert {"behavior.view", "behavior.export"} <= ALL_PERMISSION_CODES
    assert {"attention.view", "attention.edit", "attention.config", "attention.preview"} <= ALL_PERMISSION_CODES
+    assert {"records.view", "records.export"} <= ALL_PERMISSION_CODES


 def test_role_permissions_are_restricted_to_catalog() -> None:
@@ -81,6 +82,61 @@ def test_user_behavior_routes_require_behavior_permission() -> None:
        enforce_admin_access(request, denied)
    assert exc.value.status_code == 403

+    export_request = Request({"type": "http", "method": "GET", "path": "/api/admin/user-behavior/export", "headers": []})
+    with pytest.raises(HTTPException) as exc:
+        enforce_admin_access(export_request, allowed)
+    assert exc.value.status_code == 403
+
+    export_role = Role(code="behavior-exporter", name="行为报表导出", permissions=json.dumps(["behavior.export"]))
+    exporter = Admin(
+        id=6,
+        username="behavior-exporter",
+        password="hash",
+        name="行为报表导出",
+        status=1,
+        must_change_password=0,
+        is_super_admin=0,
+        role=export_role,
+    )
+    assert enforce_admin_access(export_request, exporter) is exporter
+
+
+@pytest.mark.parametrize(
+    "path",
+    [
+        "/api/admin/chat/export",
+        "/api/admin/chat/14/export",
+        "/api/admin/question-insights/export",
+    ],
+)
+def test_record_export_routes_require_export_permission(path: str) -> None:
+    viewer = Admin(
+        id=7,
+        username="records-viewer",
+        password="hash",
+        name="记录查看员",
+        status=1,
+        must_change_password=0,
+        is_super_admin=0,
+        role=Role(code="records-view", name="记录查看", permissions=json.dumps(["records.view"])),
+    )
+    request = Request({"type": "http", "method": "GET", "path": path, "headers": []})
+    with pytest.raises(HTTPException) as exc:
+        enforce_admin_access(request, viewer)
+    assert exc.value.status_code == 403
+
+    exporter = Admin(
+        id=8,
+        username="records-exporter",
+        password="hash",
+        name="记录导出员",
+        status=1,
+        must_change_password=0,
+        is_super_admin=0,
+        role=Role(code="records-export", name="记录导出", permissions=json.dumps(["records.export"])),
+    )
+    assert enforce_admin_access(request, exporter) is exporter
+

@pytest.mark.parametrize(
    ("path", "method", "permission"),
--- a/ai_knowledge_base_v2/apps/backend/tests/test_chat_export.py
+++ b/ai_knowledge_base_v2/apps/backend/tests/test_chat_export.py
@@ -0,0 +1,63 @@
+from __future__ import annotations
+
+from datetime import datetime
+
+from openpyxl import load_workbook
+
+from app.core.ai_content_label import AI_GENERATED_NOTICE
+from app.models.chat import ChatMessage, ChatSession
+from app.models.user import User
+from app.services.chat_export_service import ChatExportService
+
+
+def test_chat_export_contains_all_messages_in_order_and_ai_notice() -> None:
+    session = ChatSession(
+        id=9,
+        user_id=3,
+        title="完整对话测试",
+        message_count=99,
+        last_message_at=datetime(2026, 8, 25, 8, 2),
+        updated_at=datetime(2026, 8, 25, 8, 3),
+    )
+    user = User(id=3, phone="13800000000", name="测试学员", daily_chat_limit=10)
+    messages = [
+        ChatMessage(
+            id=21,
+            session_id=9,
+            user_id=3,
+            role="user",
+            content="第一个问题",
+            message_status="FINISHED",
+            created_at=datetime(2026, 8, 25, 8),
+        ),
+        ChatMessage(
+            id=22,
+            session_id=9,
+            user_id=3,
+            role="assistant",
+            content="第二个回答",
+            message_status="FINISHED",
+            token_input=20,
+            token_output=10,
+            response_time_ms=800,
+            created_at=datetime(2026, 8, 25, 8, 1),
+        ),
+    ]
+
+    stream = ChatExportService.build(
+        session=session,
+        user=user,
+        source_name="千问千答直接访问",
+        messages=messages,
+    )
+    workbook = load_workbook(stream)
+
+    assert workbook.sheetnames == ["会话信息", "完整对话"]
+    assert workbook["会话信息"]["B8"].value == 2
+    sheet = workbook["完整对话"]
+    assert sheet.max_row == 3
+    assert sheet["B2"].value == 21
+    assert sheet["E2"].value == "第一个问题"
+    assert sheet["B3"].value == 22
+    assert AI_GENERATED_NOTICE in sheet["E3"].value
+    assert sheet["D2"].value == datetime(2026, 8, 25, 16)
--- a/ai_knowledge_base_v2/apps/backend/tests/test_message_feedback.py
+++ b/ai_knowledge_base_v2/apps/backend/tests/test_message_feedback.py
@@ -1,6 +1,6 @@
 from __future__ import annotations

-from datetime import datetime
+from datetime import datetime, timedelta
 from types import SimpleNamespace

 from sqlalchemy import create_engine
@@ -53,5 +53,5 @@ def test_feedback_export_workbook_is_formatted_and_formula_safe() -> None:
    assert sheet["E2"].value.startswith("'=")
    assert sheet["H1"].value == "对应AI回答（AI生成）"
    assert "AI生成内容，请结合实际情况核对后使用。" in sheet["H2"].value
-    assert sheet["I2"].value == created_at
+    assert sheet["I2"].value == created_at + timedelta(hours=8)
    assert sheet.tables["FeedbackRecords"].ref == "A1:J2"
--- a/ai_knowledge_base_v2/apps/backend/tests/test_time_contract.py
+++ b/ai_knowledge_base_v2/apps/backend/tests/test_time_contract.py
@@ -0,0 +1,27 @@
+from __future__ import annotations
+
+from datetime import date, datetime
+from zoneinfo import ZoneInfo
+
+from app.core.responses import api_success
+from app.core.time_utils import business_day_boundary, to_business_naive
+
+
+def test_api_success_serializes_naive_database_time_as_explicit_utc() -> None:
+    response = api_success({"createdAt": datetime(2026, 8, 25, 8, 30, 12, 123456)})
+
+    assert response["data"]["createdAt"] == "2026-08-25T08:30:12.123Z"
+
+
+def test_api_success_normalizes_aware_business_time_to_utc() -> None:
+    response = api_success(
+        {"createdAt": datetime(2026, 8, 25, 16, 30, tzinfo=ZoneInfo("Asia/Shanghai"))}
+    )
+
+    assert response["data"]["createdAt"] == "2026-08-25T08:30:00.000Z"
+
+
+def test_beijing_day_boundary_and_excel_display_conversion() -> None:
+    assert business_day_boundary(date(2026, 8, 25)) == datetime(2026, 8, 24, 16)
+    assert business_day_boundary(date(2026, 8, 25), end_exclusive=True) == datetime(2026, 8, 25, 16)
+    assert to_business_naive(datetime(2026, 8, 25, 8, 30)) == datetime(2026, 8, 25, 16, 30)
--- a/ai_knowledge_base_v2/apps/backend/tests/test_user_behavior_analytics.py
+++ b/ai_knowledge_base_v2/apps/backend/tests/test_user_behavior_analytics.py
@@ -1,7 +1,9 @@
 from __future__ import annotations

 from datetime import UTC, datetime, timedelta
+from io import BytesIO

+from openpyxl import load_workbook
 from sqlalchemy import create_engine, select
 from sqlalchemy.orm import Session
 from sqlalchemy.pool import StaticPool
@@ -11,19 +13,27 @@ from app.models.behavior import UserBehaviorEvent
 from app.models.user import User
 from app.schemas.behavior import UserBehaviorEventCreate
 from app.services.user_behavior_service import UserBehaviorService
+from app.services.user_behavior_export_service import UserBehaviorExportService


 def _engine():
    return create_engine("sqlite:///:memory:", connect_args={"check_same_thread": False}, poolclass=StaticPool)


-def _event(event_id: str, code: str, *, target_type: str | None = None, target_id: int | None = None):
+def _event(
+    event_id: str,
+    code: str,
+    *,
+    target_type: str | None = None,
+    target_id: int | None = None,
+    occurred_at: datetime | None = None,
+):
    return UserBehaviorEventCreate(
        clientEventId=event_id,
        eventCode=code,
        targetType=target_type,
        targetId=target_id,
-        occurredAt=datetime.now(UTC),
+        occurredAt=occurred_at or datetime.now(UTC),
    )


@@ -67,18 +77,19 @@ def test_behavior_overview_user_list_and_timeline() -> None:
        ]
        db.add_all(users)
        db.commit()
+        base_time = datetime.now(UTC) - timedelta(minutes=5)
        UserBehaviorService.record_batch(
            db,
            user=users[0],
            items=[
-                _event("11111111-1111-1111-1111-111111111111", "app_open"),
-                _event("22222222-2222-2222-2222-222222222222", "send_question_click", target_type="session", target_id=3),
+                _event("11111111-1111-1111-1111-111111111111", "app_open", occurred_at=base_time),
+                _event("22222222-2222-2222-2222-222222222222", "send_question_click", target_type="session", target_id=3, occurred_at=base_time + timedelta(minutes=1)),
            ],
        )
        UserBehaviorService.record_batch(
            db,
            user=users[1],
-            items=[_event("33333333-3333-3333-3333-333333333333", "app_open")],
+            items=[_event("33333333-3333-3333-3333-333333333333", "app_open", occurred_at=base_time + timedelta(minutes=2))],
        )
        overview = UserBehaviorService.overview(db, start=None, end=None)
        assert overview["totalEvents"] == 3
@@ -90,9 +101,46 @@ def test_behavior_overview_user_list_and_timeline() -> None:
        listed = UserBehaviorService.users(db, start=None, end=None, keyword="甲", page=1, page_size=20)
        assert listed["total"] == 1
        assert listed["items"][0]["eventCount"] == 2
+        by_count = UserBehaviorService.users(
+            db,
+            start=None,
+            end=None,
+            keyword="",
+            page=1,
+            page_size=20,
+            sort_by="eventCount",
+            sort_order="asc",
+        )
+        assert [item["userName"] for item in by_count["items"]] == ["乙用户", "甲用户"]
+        by_last_time = UserBehaviorService.users(
+            db,
+            start=None,
+            end=None,
+            keyword="",
+            page=1,
+            page_size=20,
+            sort_by="lastEventAt",
+            sort_order="desc",
+        )
+        assert [item["userName"] for item in by_last_time["items"]] == ["乙用户", "甲用户"]
        timeline = UserBehaviorService.timeline(db, user_id=1, start=None, end=None, page=1, page_size=50)
        assert [item["eventName"] for item in timeline["items"]] == ["进入答疑页面", "发送问题"]

+        workbook_stream = UserBehaviorExportService.build_workbook(
+            db,
+            start=None,
+            end=None,
+            keyword="",
+            sort_by="eventCount",
+            sort_order="asc",
+        )
+        workbook = load_workbook(BytesIO(workbook_stream.getvalue()))
+        assert workbook.sheetnames == ["报表说明", "每日趋势", "功能使用频率", "用户汇总"]
+        assert workbook["报表说明"]["B11"].value == 3
+        assert workbook["用户汇总"]["B2"].value == "乙用户"
+        assert workbook["用户汇总"]["D2"].value == 1
+        assert workbook["用户汇总"]["C2"].number_format == "@"
+

 def test_behavior_retention_deletes_only_expired_rows() -> None:
    engine = _engine()
--- a/ai_knowledge_base_v2/apps/user-client/src/components/ChatMessage.vue
+++ b/ai_knowledge_base_v2/apps/user-client/src/components/ChatMessage.vue
@@ -2,6 +2,7 @@
 import { Bot, MessageSquareWarning, RotateCcw } from "@lucide/vue";
 import MarkdownIt from "markdown-it";
 import { computed } from "vue";
+import { formatTime } from "../utils/dateTime";

 const props = defineProps<{
  messageId: string;
@@ -79,10 +80,7 @@ function splitReasoning(content: string) {
 }

 const displayTime = computed(() => {
-  const normalized = /(?:Z|[+-]\d{2}:?\d{2})$/i.test(props.createdAt) ? props.createdAt : `${props.createdAt}Z`;
-  const date = new Date(normalized);
-  if (Number.isNaN(date.getTime())) return "";
-  return new Intl.DateTimeFormat("zh-CN", { hour: "2-digit", minute: "2-digit", hour12: false }).format(date);
+  return formatTime(props.createdAt, "");
 });
 </script>

--- a/ai_knowledge_base_v2/apps/user-client/src/components/PersonalCenterDialog.vue
+++ b/ai_knowledge_base_v2/apps/user-client/src/components/PersonalCenterDialog.vue
@@ -16,6 +16,7 @@ import {
 import { computed, ref, watch } from "vue";

 import type { PeriodicReport, PracticeReviewResult, ShareDraft, TeacherHelpCard, UserProfile } from "../types/api";
+import { formatDate } from "../utils/dateTime";
 import AppDialog from "./AppDialog.vue";

 type CenterSection = "overview" | "review" | "reports" | "records";
@@ -104,13 +105,6 @@ function usagePercent(used: number, limit: number | null) {
  return Math.min(100, Math.max(0, Math.round((used / limit) * 100)));
 }

-function formatDate(value?: string | null) {
-  if (!value) return "长期有效";
-  const date = new Date(value);
-  if (Number.isNaN(date.getTime())) return value;
-  return date.toLocaleDateString("zh-CN", { year: "numeric", month: "2-digit", day: "2-digit" });
-}
-
 function settlementStatusLabel(status: string) {
  return {
    pending: "等待整理",
@@ -189,7 +183,7 @@ function submitDeleteCard() {
            </div>
            <div>
              <dt>有效期至</dt>
-              <dd>{{ formatDate(entitlement?.expiredAt) }}</dd>
+              <dd>{{ formatDate(entitlement?.expiredAt, "长期有效") }}</dd>
            </div>
          </dl>
        </article>
--- a/ai_knowledge_base_v2/apps/user-client/src/components/SessionDrawer.vue
+++ b/ai_knowledge_base_v2/apps/user-client/src/components/SessionDrawer.vue
@@ -4,6 +4,7 @@ import { computed, ref, watch } from "vue";

 import type { ChatSession } from "../types/api";
 import AppDialog from "./AppDialog.vue";
+import { formatSessionTime } from "../utils/dateTime";

 const props = defineProps<{
  open: boolean;
@@ -50,18 +51,6 @@ function submitDelete() {
  });
 }

-function formatTime(value: string) {
-  const date = new Date(value);
-  if (Number.isNaN(date.getTime())) return "";
-  const now = new Date();
-  const today = new Date(now.getFullYear(), now.getMonth(), now.getDate());
-  const target = new Date(date.getFullYear(), date.getMonth(), date.getDate());
-  const days = Math.round((today.getTime() - target.getTime()) / 86_400_000);
-  const time = new Intl.DateTimeFormat("zh-CN", { hour: "2-digit", minute: "2-digit", hour12: false }).format(date);
-  if (days === 0) return time;
-  if (days === 1) return `昨天 ${time}`;
-  return `${String(date.getMonth() + 1).padStart(2, "0")}/${String(date.getDate()).padStart(2, "0")} ${time}`;
-}
 </script>

 <template>
@@ -91,7 +80,7 @@ function formatTime(value: string) {
      >
        <button type="button" class="history-main" @click="emit('select', session.id)">
          <strong>{{ session.title }}</strong>
-          <time :datetime="session.updatedAt">{{ formatTime(session.updatedAt) }}</time>
+          <time :datetime="session.updatedAt">{{ formatSessionTime(session.updatedAt) }}</time>
          <span>{{ session.messageCount }} 条消息</span>
        </button>
        <div class="history-actions">
--- a/ai_knowledge_base_v2/apps/user-client/src/components/SessionQuota.vue
+++ b/ai_knowledge_base_v2/apps/user-client/src/components/SessionQuota.vue
@@ -3,6 +3,7 @@ import { Layers3, LoaderCircle } from "@lucide/vue";
 import { computed } from "vue";

 import type { UserEntitlementSummary } from "../types/api";
+import { formatDate } from "../utils/dateTime";

 const props = defineProps<{
  used: number;
@@ -26,11 +27,6 @@ const usageText = computed(() => {
  if (displayLimit.value <= 0) return "今日不可用";
  return `今日 ${displayUsed.value}/${displayLimit.value} 次`;
 });
-function formatDate(value?: string | null) {
-  if (!value) return "";
-  const date = new Date(value);
-  return Number.isNaN(date.getTime()) ? value : date.toLocaleDateString("zh-CN");
-}
 const guidanceText = computed(() => {
  if (props.entitlement?.lifecycleStatus === "expired_fallback") {
    return `原${props.entitlement.previousPlanName ? `“${props.entitlement.previousPlanName}”` : "权益"}已于 ${formatDate(props.entitlement.previousExpiredAt)} 到期，当前已自动切换为${props.entitlement.name}，已有对话与回顾仍会保留。`;
--- a/ai_knowledge_base_v2/apps/user-client/src/utils/dateTime.ts
+++ b/ai_knowledge_base_v2/apps/user-client/src/utils/dateTime.ts
@@ -0,0 +1,76 @@
+export const BUSINESS_TIME_ZONE = "Asia/Shanghai";
+const BUSINESS_OFFSET = "+08:00";
+const DATE_ONLY_PATTERN = /^\d{4}-\d{2}-\d{2}$/;
+const EXPLICIT_OFFSET_PATTERN = /(?:Z|[+-]\d{2}:?\d{2})$/i;
+
+export function parseApiDateTime(value?: string | Date | null): Date | null {
+  if (!value) return null;
+  if (value instanceof Date) return Number.isNaN(value.getTime()) ? null : value;
+  const text = value.trim();
+  if (!text) return null;
+  const isoText = text.includes(" ") ? text.replace(" ", "T") : text;
+  const normalized = DATE_ONLY_PATTERN.test(isoText)
+    ? `${isoText}T00:00:00${BUSINESS_OFFSET}`
+    : EXPLICIT_OFFSET_PATTERN.test(isoText)
+      ? isoText
+      : `${isoText}Z`;
+  const parsed = new Date(normalized);
+  return Number.isNaN(parsed.getTime()) ? null : parsed;
+}
+
+function businessParts(value?: string | Date | null) {
+  const parsed = parseApiDateTime(value);
+  if (!parsed) return null;
+  const parts = new Intl.DateTimeFormat("zh-CN", {
+    timeZone: BUSINESS_TIME_ZONE,
+    year: "numeric",
+    month: "2-digit",
+    day: "2-digit",
+    hour: "2-digit",
+    minute: "2-digit",
+    second: "2-digit",
+    hour12: false,
+    hourCycle: "h23",
+  }).formatToParts(parsed);
+  return Object.fromEntries(parts.map((part) => [part.type, part.value]));
+}
+
+export function formatDate(value?: string | Date | null, fallback = "-") {
+  const parts = businessParts(value);
+  return parts ? `${parts.year}-${parts.month}-${parts.day}` : fallback;
+}
+
+export function formatTime(value?: string | Date | null, fallback = "-") {
+  const parts = businessParts(value);
+  return parts ? `${parts.hour}:${parts.minute}` : fallback;
+}
+
+export function formatDateTime(value?: string | Date | null, fallback = "-") {
+  const parts = businessParts(value);
+  return parts
+    ? `${parts.year}-${parts.month}-${parts.day} ${parts.hour}:${parts.minute}:${parts.second}`
+    : fallback;
+}
+
+export function businessDateKey(value?: string | Date | null): string | null {
+  const parts = businessParts(value);
+  return parts ? `${parts.year}-${parts.month}-${parts.day}` : null;
+}
+
+export function formatSessionTime(
+  value?: string | Date | null,
+  now: Date = new Date(),
+): string {
+  const targetKey = businessDateKey(value);
+  const todayKey = businessDateKey(now);
+  const time = formatTime(value, "");
+  if (!targetKey || !todayKey || !time) return "";
+  const dayNumber = (key: string) => {
+    const [year, month, day] = key.split("-").map(Number);
+    return Date.UTC(year, month - 1, day) / 86_400_000;
+  };
+  const days = dayNumber(todayKey) - dayNumber(targetKey);
+  if (days === 0) return time;
+  if (days === 1) return `昨天 ${time}`;
+  return `${targetKey.slice(5).replace("-", "/")} ${time}`;
+}