feat(web): AI 工作台文件预览/附件关联任务与草稿分支

- 新增 WorkbenchAiFilePreviewDialog 附件预览对话框及 useWorkbenchAiFilePreview，附件支持点击预览
- 新增 attachmentAssociationJobs/linkedReimbursementDraftJobs 前端服务与对应 composable，接入后台任务轮询与状态展示
- 新增 travelReimbursementDraftBranchModel 草稿分支模型，报销关联门控支持跳过/选择草稿
- PersonalWorkbenchAiMode 及各 composable（expense/document/steward/application-preview/attachment-association）重构适配，WorkbenchAiComposer/FileStrip 样式与交互完善
- DocumentsCenter/ReceiptFolder/TravelReimbursementCreate 等视图及 scripts 重构，风险/差旅规划/审批等工具适配
- 新增/更新前端测试：application-result-card、reimbursement-list-preview-fetch、guided-flow、composer-components 等

web/tests/workbench-composer-date.test.mjs

@@ -2,7 +2,9 @@ import assert from 'node:assert/strict'
 import { readFileSync } from 'node:fs'
 import test from 'node:test'
 import { fileURLToPath } from 'node:url'
+import { ref } from 'vue'
 
+import { useWorkbenchComposerDate } from '../src/composables/useWorkbenchComposerDate.js'
 import {
   buildWorkbenchDateLabel,
   canApplyWorkbenchDateSelection,
@@ -76,3 +78,34 @@ test('workbench date helper builds labels and inserts them into draft text', ()
   )
   assert.equal(canApplyWorkbenchDateSelection({ mode: 'range', rangeStartDate: '2026-06-01', rangeEndDate: '2026-05-31' }), false)
 })
+
+test('workbench range end date changes keep the picker open until the user confirms', () => {
+  const draft = ref('')
+  let focusCount = 0
+  const dateRuntime = useWorkbenchComposerDate({
+    draft,
+    focusInput: () => {
+      focusCount += 1
+    }
+  })
+
+  dateRuntime.workbenchDatePickerOpen.value = true
+  dateRuntime.workbenchDateMode.value = 'range'
+  dateRuntime.workbenchRangeStartDate.value = '2026-02-20'
+  dateRuntime.workbenchRangeEndDate.value = '2026-03-23'
+
+  dateRuntime.handleWorkbenchDateInputChange('range-end')
+
+  assert.equal(dateRuntime.workbenchDatePickerOpen.value, true)
+  assert.equal(dateRuntime.workbenchDateTagLabel.value, '')
+  assert.equal(draft.value, '')
+  assert.equal(focusCount, 0)
+
+  dateRuntime.applyWorkbenchDateSelection()
+
+  assert.equal(dateRuntime.workbenchDatePickerOpen.value, false)
+  assert.equal(dateRuntime.workbenchDateTagLabel.value, '2026-02-20 至 2026-03-23')
+  assert.equal(draft.value, '')
+  assert.equal(dateRuntime.buildWorkbenchPromptText(), '2026-02-20 至 2026-03-23')
+  assert.equal(focusCount, 1)
+})