文件下载名称调优

src/Jiaowu.Api/Controllers/ExamsController.cs

@@ -6,6 +6,7 @@ using Jiaowu.Api.Infrastructure.Auth;
 using Jiaowu.Api.Infrastructure.Caching;
 using Jiaowu.Api.Infrastructure.Exams;
 using Jiaowu.Api.Infrastructure.Excel;
+using Jiaowu.Api.Infrastructure.Files;
 using Jiaowu.Api.Infrastructure.Persistence;
 using Jiaowu.Api.Infrastructure.Teaching;
 using Microsoft.AspNetCore.Authorization;
@@ -1144,7 +1145,7 @@ public sealed class ExamsController(
         return File(
             bytes,
             ExcelWorkbookHelper.ContentType,
-            $"考场签名单-{FileNamePart(plan.Name)}.xlsx");
+            DownloadFileName.Export("考场签名单", ".xlsx", plan.Name));
     }
 
     // ═══════════════════════════════════════════
@@ -1227,7 +1228,7 @@ public sealed class ExamsController(
         return File(
             job.FileBytes,
             ExcelWorkbookHelper.ContentType,
-            job.FileName ?? "考场签名单.xlsx");
+            job.FileName ?? DownloadFileName.Export("考场签名单", ".xlsx"));
     }
 
     // ═══════════════════════════════════════════