style(web): 更新差旅报销创建页面样式和业务脚本，增强前端交互和状态管理

web/src/views/scripts/TravelRequestDetailView.js

@@ -7,8 +7,8 @@ import {
   deleteExpenseClaimItem,
   deleteExpenseClaimItemAttachment,
   deleteExpenseClaim,
-  fetchExpenseClaimItemAttachment,
   fetchExpenseClaimItemAttachmentMeta,
+  fetchExpenseClaimItemAttachmentPreview,
   submitExpenseClaim,
   uploadExpenseClaimItemAttachment,
   updateExpenseClaimItem
@@ -894,10 +894,14 @@ export default {
       attachmentPreviewOpen.value = true
       attachmentPreviewLoading.value = true
       attachmentPreviewName.value = resolveAttachmentDisplayName(item)
-      attachmentPreviewMediaType.value = String(resolveAttachmentMeta(item)?.media_type || '').trim()
+      const metadata = resolveAttachmentMeta(item)
+      attachmentPreviewMediaType.value =
+        String(metadata?.preview_kind || '').trim() === 'image'
+          ? 'image/png'
+          : String(metadata?.media_type || '').trim()
 
       try {
-        const blob = await fetchExpenseClaimItemAttachment(request.value.claimId, item.id)
+        const blob = await fetchExpenseClaimItemAttachmentPreview(request.value.claimId, item.id)
         revokeAttachmentPreviewUrl()
         attachmentPreviewUrl.value = URL.createObjectURL(blob)
         attachmentPreviewMediaType.value = blob.type || attachmentPreviewMediaType.value
@@ -1139,7 +1143,8 @@ export default {
       emit('openAssistant', {
         source: 'detail',
         prompt: '',
-        request: request.value
+        request: request.value,
+        restoreLatestConversation: true
       })
     }