feat(web): 设置中心缓存管理与文件预览资产工具

- 新增 documentPreviewAssets 工具，统一从 URL/Blob/File 推断预览类型（image/pdf/file/unsupported）
- SettingsView/SettingsView.js/settingsModelHelper 新增系统缓存管理区块，调用 /settings/cache/clear 并展示清理结果；useSettings/services 适配
- WorkbenchAiFilePreviewDialog/useWorkbenchAiFilePreview 接入预览资产工具，workbenchAiComposerModel 调整文件处理
- ReceiptFolder/LogDetailView/DigitalEmployeeWorkRecords/travelReimbursementAttachmentModel 配套适配
- 新增 settings-cache-management-section 测试，更新 settings-llm/rendering/receipt-folder-view/composer-components/attachment-association 测试

web/tests/attachment-association-confirmation.test.mjs

@@ -131,7 +131,7 @@ test('attachment upload association uses conversation selection instead of legac
   assert.doesNotMatch(submitComposerSource, /查询可关联草稿失败，已继续按新单据识别/)
   assert.match(
     submitDraftPreflightSource,
-    /const claims = await fetchExpenseClaims\(\)[\s\S]*const queryPayload = buildDraftAssociationQueryPayload\(claims\)[\s\S]*meta: \['等待选择关联单据'\][\s\S]*queryPayload/
+    /const claims = await fetchExpenseClaims\([^)]*\)[\s\S]*const queryPayload = buildDraftAssociationQueryPayload\(claims\)[\s\S]*meta: \['等待选择关联单据'\][\s\S]*queryPayload/
   )
   assert.match(submitDraftPreflightSource, /meta: \['单据查询失败'\][\s\S]*return \{ handled: true, value: null \}/)
   assert.match(
@@ -186,6 +186,26 @@ test('OCR preview builders keep hotel receipt image previews when preview kind i
   assert.deepEqual(reviewPreviews, [{ filename: 'hotel.png', kind: 'image', url: dataUrl }])
 })
 
+test('OCR preview builders reuse receipt folder image preview endpoints', () => {
+  const ocrPreviews = buildOcrFilePreviews({
+    documents: [
+      {
+        filename: '2月23 上海-武汉.pdf',
+        preview_kind: 'image',
+        receipt_preview_url: '/receipt-folder/receipt-train-1/preview'
+      }
+    ]
+  })
+
+  assert.deepEqual(ocrPreviews, [
+    {
+      filename: '2月23 上海-武汉.pdf',
+      kind: 'image',
+      url: '/receipt-folder/receipt-train-1/preview'
+    }
+  ])
+})
+
 test('OCR receipt folder ids are kept for final draft attachment association', () => {
   const files = [
     { name: 'invoice.png' },