fix

Service/Jobs/DbBackupJob.cs

@@ -15,7 +15,7 @@ public class DbBackupJob(
         try
         {
             logger.LogInformation("开始执行数据库备份任务");
-            
+
             // 数据库文件路径 (基于 appsettings.json 中的配置: database/EmailBill.db)
             var dbPath = Path.Combine(env.ContentRootPath, "database", "EmailBill.db");
             var backupDir = Path.Combine(env.ContentRootPath, "database", "backups");
@@ -48,7 +48,7 @@ public class DbBackupJob(
                 var filesToDelete = files.Skip(20);
                 foreach (var file in filesToDelete)
                 {
-                    try 
+                    try
                     {
                         file.Delete();
                         logger.LogInformation("删除过期备份: {Name}", file.Name);