功能(文档预览)：集成 ONLYOFFICE 安全只读预览与工作台体验

新增 ONLYOFFICE 配置签名、内部内容接口、容器编排与反向代理。

打通网页端和桌面端独立预览工作区，完善文档入口、布局及帮助体验。

补充桌面安全发布门禁、开发脚本、使用文档和前后端测试。

frontend/src/components/attachments/AttachmentList.vue

@@ -163,6 +163,7 @@
 
 <script setup lang="ts">
 import { computed, defineAsyncComponent, onMounted, reactive, ref, watch } from "vue";
+import { useRouter } from "vue-router";
 import { ElMessage, ElMessageBox } from "element-plus";
 import { Document, UploadFilled } from "@element-plus/icons-vue";
 import { fetchAttachments, deleteAttachment, downloadAttachment, uploadAttachment } from "../../api/attachments";
@@ -177,6 +178,7 @@ import { TEXT } from "../../locales";
 import { clientRuntime } from "../../runtime";
 import { openFileWithFeedback, pickFilesWithFeedback, saveFileWithFeedback } from "../../utils/fileTaskFeedback";
 import { finishDesktopActivity, startDesktopActivity, updateDesktopActivity } from "../../session/desktopActivityCenter";
+import { detectFilePreviewKind } from "../../utils/officePreview";
 
 type AttachmentEntityGroup = {
   entityType: string;
@@ -223,6 +225,7 @@ const progressMap = reactive<Record<string, number>>({});
 const pendingMap = reactive<Record<string, PendingUploadItem[]>>({});
 const auth = useAuthStore();
 const study = useStudyStore();
+const router = useRouter();
 const previewVisible = ref(false);
 const previewUrl = ref("");
 const previewObjectUrl = ref("");
@@ -518,17 +521,8 @@ const openExternally = async (row: any) => {
   }
 };
 
-const getFileName = (row: any) => (row?.filename || "").toLowerCase();
-const getMimeType = (row: any) => (row?.mime_type || row?.content_type || "").toLowerCase();
-
 const detectPreviewType = (row: any) => {
-  const mime = getMimeType(row);
-  if (mime.startsWith("image/")) return "image";
-  if (mime === "application/pdf") return "pdf";
-  const name = getFileName(row);
-  if ([".png", ".jpg", ".jpeg", ".gif", ".bmp", ".webp", ".svg"].some((ext) => name.endsWith(ext))) return "image";
-  if (name.endsWith(".pdf")) return "pdf";
-  return "other";
+  return detectFilePreviewKind(row?.filename, row?.mime_type || row?.content_type);
 };
 
 const previewImage = async (row: any) => {
@@ -547,7 +541,12 @@ const previewImage = async (row: any) => {
 
 const preview = async (row: any) => {
   previewError.value = "";
-  previewType.value = detectPreviewType(row);
+  const detectedType = detectPreviewType(row);
+  if (detectedType === "office") {
+    await router.push(`/office-preview/attachment/${row.id}`);
+    return;
+  }
+  previewType.value = detectedType;
   previewTitle.value = row?.filename || TEXT.common.labels.preview;
   if (previewType.value === "image" || previewType.value === "pdf") {
     previewUrl.value = "";