perf(base-卡2c): FilePreviewPanel 的 VueOfficeDocx 改 defineAsyncComponent，xlsx 改 parseExcel 内 await import 按需加载

src/views/ventAI/manageAssistent/components/chatModal/FilePreviewPanel.vue

@@ -101,11 +101,9 @@
 </template>
 
 <script setup lang="ts">
-  import { ref, computed, watch, onUnmounted } from 'vue';
+  import { ref, computed, watch, onUnmounted, defineAsyncComponent } from 'vue';
   import { message } from 'ant-design-vue';
   import { saveReportText } from '../../api';
-  import VueOfficeDocx from '@vue-office/docx/lib/v3/vue-office-docx.mjs';
-  import * as XLSX from 'xlsx';
   import {
     isImageFile,
     isPdfFile,
@@ -122,6 +120,10 @@
   } from './utils';
   import type { AttachedFile } from './types';
 
+  // [perf-base-v1] 卡2c: VueOfficeDocx 改异步加载，仅打开 docx 预览时才拉取 office-preview chunk
+  const VueOfficeDocx = defineAsyncComponent(() => import('@vue-office/docx/lib/v3/vue-office-docx.mjs'));
+  // [perf-base-v1] 卡2c: xlsx 改为 parseExcel 内 await import 按需加载（见下）
+
   const getCssUrl = (varName: string) => {
     const val = getComputedStyle(document.documentElement).getPropertyValue(varName).trim();
     return val.replace(/^url\(["']?/, '').replace(/["']?\)$/, '');
@@ -209,6 +211,8 @@
         buffer = await file.originalFile.arrayBuffer();
       }
       if (!buffer) return;
+      // [perf-base-v1] 卡2c: 仅在解析 Excel 时才动态加载 xlsx 库
+      const XLSX = await import('xlsx');
       const workbook = XLSX.read(buffer, { type: 'array' });
       excelSheets.value = workbook.SheetNames.map((name) => {
         const sheet = workbook.Sheets[name];