namespace WorkTracker.Services.Exports; public interface IMonthlyTimesheetExcelExportService { Task ExportAsync(int year, int month, bool includePreview, CancellationToken cancellationToken = default); } public sealed class MonthlyTimesheetExcelFile { public required string FileName { get; init; } public required byte[] Content { get; init; } public string ContentType => "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"; }