新增: HTML预览导出PDF并兼容Edge环境

- chromedp 通道新增源文件入口,file:// 加载原始HTML
- 相对资源在原目录天然解析,printBackground 保背景色
- 预览工具栏新增导出按钮,默认文件名取当前HTML名
- 远程文件复用站点缓存路径,本地远程同一命令
- 浏览器探测扩Chrome+Edge双查,Markdown通道重复探测归一

frontend/src/components/FileSystem/components/FileEditorPanel.vue

@@ -210,6 +210,17 @@
               <template #icon><icon-save /></template>
             </a-button>
           </a-tooltip>
+          <!-- PDF 导出按钮（仅预览模式显示，后端 Chrome 渲染输出到桌面） -->
+          <a-tooltip v-if="!config.isEditMode" position="left" content="导出 PDF">
+            <a-button
+              type="outline"
+              size="small"
+              :loading="htmlExporting"
+              @click="handleExportHtmlPDF"
+            >
+              <template #icon><icon-file-pdf /></template>
+            </a-button>
+          </a-tooltip>
           <!-- 预览/编辑切换按钮 -->
           <a-tooltip
             position="left"
@@ -440,6 +451,7 @@ import { previewExcel, previewWord, previewCsv } from '@/utils/filePreviewHandle
 import { getFileCategory, isAudioFile } from '@/utils/fileTypeHelpers'
 import { isDirty } from '../composables/useMultiPreview'
 import { On, Off } from '@wailsio/events'
+import { ExportHtmlFileToPDF } from '@bindings/u-desk/app'
 import { connectionManager } from '@/api/connection-manager'
 import { listDir, readFile } from '@/api/system'
 import { resolveFileUrl, resolveFileUrlForProfile } from '../composables/useFilePreview'
@@ -528,32 +540,39 @@ const getFileTypeIcon = (filename: string): string => {
 
 // HTML 预览 URL（OSS 需要先下载到本地再预览）
 const htmlPreviewUrl = ref('')
+// 导出 PDF 需要本地可访问的源文件路径：远程文件取缓存副本，本地文件即原路径
+const htmlPreviewLocalPath = ref('')
 
 watch(
   () => [props.config.currentFileFullPath, props.config.isHtmlFile],
   async ([path, isHtml]) => {
     htmlPreviewUrl.value = ''
+    htmlPreviewLocalPath.value = ''
     if (!path || !isHtml) return
 
     // 下载到临时目录后是本地文件，统一用本地文件服务器
     const base = getFileServerBaseURL()
     const makeUrl = (localPath: string) => `${base}/localfs/html-preview?path=${encodeURIComponent(localPath)}`
+    const applyLocalPath = (localPath: string) => {
+      htmlPreviewLocalPath.value = localPath
+      htmlPreviewUrl.value = makeUrl(localPath)
+    }
 
     if (connectionManager.isRemote()) {
       try {
         const transport = connectionManager.getTransport()
         if (transport?.downloadSiteForPreview) {
           const tempPath = await transport.downloadSiteForPreview(path)
-          htmlPreviewUrl.value = makeUrl(tempPath)
+          applyLocalPath(tempPath)
         } else if (transport?.downloadForPreview) {
           const tempPath = await transport.downloadForPreview(path)
-          htmlPreviewUrl.value = makeUrl(tempPath)
+          applyLocalPath(tempPath)
         }
       } catch (e) {
         console.warn('[HTML预览] 下载失败:', path, e)
       }
     } else {
-      htmlPreviewUrl.value = makeUrl(path)
+      applyLocalPath(path)
     }
   },
   { immediate: true }
@@ -897,6 +916,31 @@ const handleExportCsvPDF = async () => {
   )
 }
 
+// HTML 文件导出 PDF：交给后端 headless Chrome 渲染，绕开浏览器打印对话框
+const htmlExporting = ref(false)
+const handleExportHtmlPDF = async () => {
+  const srcPath = htmlPreviewLocalPath.value
+  if (!srcPath) {
+    Message.error('HTML 预览尚未就绪，请稍候重试')
+    return
+  }
+  const baseName = (props.config.currentFileName || 'export').replace(/\.[^.]+$/, '')
+  htmlExporting.value = true
+  try {
+    const res = await ExportHtmlFileToPDF(srcPath, baseName)
+    if (res?.success) {
+      Message.success(`PDF 已导出到: ${res.path}`)
+    } else {
+      Message.error(res?.message || 'PDF 导出失败')
+    }
+  } catch (e: any) {
+    // 后端约定的错误文案随异常抛出，无 Chrome 时向用户展示安装提示
+    Message.error(e?.message || 'PDF 导出失败')
+  } finally {
+    htmlExporting.value = false
+  }
+}
+
 // 监听模式切换，切换到预览模式时渲染 Mermaid 图表
 watch(() => props.config.isEditMode, async (newVal, oldVal) => {
   // 从编辑模式切换到预览模式