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/workbench-ai-composer-components.test.mjs

@@ -3,6 +3,8 @@ import { readFileSync } from 'node:fs'
 import test from 'node:test'
 import { fileURLToPath } from 'node:url'
 
+import { buildSelectedFileCards } from '../src/composables/workbenchAiMode/workbenchAiComposerModel.js'
+
 function readSource(path) {
   return readFileSync(fileURLToPath(new URL(path, import.meta.url)), 'utf8')
 }
@@ -49,6 +51,31 @@ test('shared workbench file strip preserves OCR status badges', () => {
   assert.match(fileStripComponent, /:title="file\.ocrState\.title \|\| file\.ocrState\.label"/)
 })
 
+test('shared workbench file strip uses recognized image preview metadata over raw PDF type', () => {
+  const [card] = buildSelectedFileCards([
+    {
+      name: '2月23 上海-武汉.pdf',
+      type: 'application/pdf',
+      size: 24940,
+      lastModified: 1760000000000
+    }
+  ], () => ({
+    status: 'recognized',
+    document: {
+      preview_kind: 'image',
+      receipt_preview_url: '/receipt-folder/receipt-train-1/preview'
+    }
+  }))
+
+  assert.equal(card.tone, 'image')
+  assert.equal(card.icon, 'mdi mdi-file-image-outline')
+  assert.deepEqual(card.previewAsset, {
+    kind: 'image',
+    url: '/receipt-folder/receipt-train-1/preview',
+    source: 'receipt'
+  })
+})
+
 test('AI mode primes attachment OCR synchronously after file selection', () => {
   assert.match(
     filePreviewRuntime,