isSessionExpired method
Verifica si la sesión actual ha expirado
Implementation
bool isSessionExpired(int maxLengthMins) {
final timestamp = getSessionTimestamp();
if (timestamp == null) return true;
final now = DateTime.now().millisecondsSinceEpoch;
final sessionAge = now - timestamp;
final maxSessionLength = Duration(minutes: maxLengthMins).inMilliseconds;
return sessionAge >= maxSessionLength;
}