feat: 完善知识库、策略预览与OnlyOffice集成，增强后端启动依赖检查

web/tests/knowledge-preview-mode.test.mjs

@@ -0,0 +1,39 @@
+import assert from 'node:assert/strict'
+
+import { resolveKnowledgePreviewMode } from '../src/views/scripts/knowledgePreviewMode.js'
+
+function testPrefersOnlyOfficeForSupportedOfficeFileWhenAvailable() {
+  const document = {
+    extension: 'xlsx',
+    previewKind: 'table'
+  }
+
+  assert.equal(resolveKnowledgePreviewMode(document, { onlyOfficeAvailable: true }), 'onlyoffice')
+}
+
+function testFallsBackToStructuredPreviewForOfficeFileWhenOnlyOfficeUnavailable() {
+  const document = {
+    extension: 'xlsx',
+    previewKind: 'table'
+  }
+
+  assert.equal(resolveKnowledgePreviewMode(document, { onlyOfficeAvailable: false }), 'table')
+}
+
+function testUsesPreviewKindForNonOnlyOfficeFile() {
+  const document = {
+    extension: 'pdf',
+    previewKind: 'pdf'
+  }
+
+  assert.equal(resolveKnowledgePreviewMode(document, { onlyOfficeAvailable: false }), 'pdf')
+}
+
+function run() {
+  testPrefersOnlyOfficeForSupportedOfficeFileWhenAvailable()
+  testFallsBackToStructuredPreviewForOfficeFileWhenOnlyOfficeUnavailable()
+  testUsesPreviewKindForNonOnlyOfficeFile()
+  console.log('knowledge preview mode tests passed')
+}
+
+run()