修复报销附件上传与中文文件名（07-28-travel-reimbursement-guide）

client/src/api/errorMessages.ts

@@ -359,6 +359,12 @@ export function mapApiErrorMessage(
       return "附件超过大小限制，请压缩后重新上传。";
     }
 
+    if (details?.file === "too_many_files") {
+      return details?.maxFiles === 5
+        ? "单次最多上传 5 个附件，请分批上传。"
+        : "一次选择的附件过多，请减少数量后分批上传。";
+    }
+
     if (details?.file === "dangerous_filename") {
       return "附件名称不安全，请重命名后重新上传。";
     }

client/src/api/reimbursements.ts

@@ -490,6 +490,8 @@ export async function deleteReimbursementItem(reimbursementId: string, itemId: s
   );
 }
 
+export const MAX_REIMBURSEMENT_ATTACHMENT_FILES = 5;
+
 export async function uploadReimbursementAttachments(reimbursementId: string, files: File[]) {
   const formData = new FormData();
   for (const file of files) {