feat: 完善知识库、策略预览与OnlyOffice集成

## 配置与环境
- .env.example: 更新环境变量配置
- docker-compose.yml: 完善Docker编排配置
- docker/README.md: 更新Docker文档

## 后端知识库模块
- endpoints/knowledge.py: 增强知识库API端点
- schemas/knowledge.py: 扩展知识库数据模型
- services/knowledge.py: 完善知识库业务逻辑
- config.py: 优化配置管理
- storage/knowledge/.index.json: 更新知识库索引

## 前端功能
- api.js: 完善API服务层
- knowledge.js: 优化知识库服务
- onlyoffice.js: 新增OnlyOffice文档服务集成
- TopBar.vue: 优化顶部导航栏
- PoliciesView.vue: 完善策略视图
- AppShellRouteView.vue: 新增应用外壳路由视图
- views/scripts/PoliciesView.js: 优化策略脚本
- policiesPreviewFormatters.js: 新增策略预览格式化工具

## 样式
- policies-view.css: 完善策略页样式

## 测试
- api-request.test.mjs: API请求测试
- onlyoffice-service.test.mjs: OnlyOffice服务测试
- policies-preview-formatters.test.mjs: 策略预览格式化测试

web/src/services/onlyoffice.js

@@ -0,0 +1,43 @@
+const scriptPromises = new Map()
+
+function normalizeBaseUrl(value) {
+  return String(value || '').replace(/\/$/, '')
+}
+
+export function buildOnlyOfficeScriptUrl(documentServerUrl) {
+  return `${normalizeBaseUrl(documentServerUrl)}/web-apps/apps/api/documents/api.js`
+}
+
+export function loadOnlyOfficeApi(documentServerUrl) {
+  const scriptUrl = buildOnlyOfficeScriptUrl(documentServerUrl)
+  if (typeof window === 'undefined') {
+    return Promise.reject(new Error('ONLYOFFICE 只能在浏览器环境中加载。'))
+  }
+
+  if (window.DocsAPI?.DocEditor) {
+    return Promise.resolve(window.DocsAPI)
+  }
+
+  if (scriptPromises.has(scriptUrl)) {
+    return scriptPromises.get(scriptUrl)
+  }
+
+  const promise = new Promise((resolve, reject) => {
+    const existing = document.querySelector(`script[src="${scriptUrl}"]`)
+    if (existing) {
+      existing.addEventListener('load', () => resolve(window.DocsAPI), { once: true })
+      existing.addEventListener('error', () => reject(new Error('ONLYOFFICE 脚本加载失败。')), { once: true })
+      return
+    }
+
+    const script = document.createElement('script')
+    script.src = scriptUrl
+    script.async = true
+    script.onload = () => resolve(window.DocsAPI)
+    script.onerror = () => reject(new Error('ONLYOFFICE 脚本加载失败。'))
+    document.head.appendChild(script)
+  })
+
+  scriptPromises.set(scriptUrl, promise)
+  return promise
+}