实现企微原生材料预览（07-27-yang-jun-reimbursement-readiness）

client/src/api/reimbursements.ts

@@ -175,6 +175,8 @@ export type ReimbursementDetail = {
     sellerName: string | null;
     totalAmount: string | null;
     originalName: string | null;
+    mimeType: string | null;
+    fileSize: number | null;
     linkedItemId: string | null;
   }>;
   attachments: Array<{
@@ -525,6 +527,23 @@ export async function downloadReimbursementAttachment(reimbursementId: string, a
   return apiRequestBlob(buildAttachmentFileUrl(reimbursementAttachmentFileUrl(reimbursementId, attachmentId), reason));
 }
 
+export async function fetchReimbursementAttachmentPreviewUrl(
+  reimbursementId: string,
+  attachmentId: string,
+  reason?: string,
+) {
+  return apiRequestData<{
+    signedUrl: string;
+    expiresAt: string;
+    originalName: string;
+    mimeType: string;
+    fileSize: number;
+  }>(`/api/reimbursements/${reimbursementId}/attachments/${attachmentId}/preview-url`, {
+    method: "POST",
+    body: JSON.stringify(reason ? { reason } : {}),
+  });
+}
+
 
 export async function linkReimbursementProject(reimbursementId: string, projectId: string | null) {
   return apiRequestData<{ projectId: string | null; project: { id: string; projectNo: string; name: string } | null }>(`/api/reimbursements/${reimbursementId}/link-project`, {