isTaskOverdue method
Implementation
bool isTaskOverdue(GanttTask task) {
if (task.progress == null) return false;
final today = DateTime.now();
final endDate = DateTime(task.end.year, task.end.month, task.end.day);
final todayDate = DateTime(today.year, today.month, today.day);
return endDate.isBefore(todayDate) && task.progress! < 1.0;
}