// ────────────────────────────────────────────────────────────────────────
//  date_utils.dart   – helper shared by all models
// ────────────────────────────────────────────────────────────────────────
DateTime? parseDate(dynamic raw) {
  if (raw == null) return null;
  if (raw is String) return DateTime.parse(raw);
  if (raw is int) return DateTime.fromMillisecondsSinceEpoch(raw);
  if (raw is List && raw.length >= 6) {
    // Spring's LocalDateTime serialized as [yyyy,MM,dd,HH,mm,ss,nanos]
    return DateTime(raw[0], raw[1], raw[2], raw[3], raw[4], raw[5],
        raw.length > 6 ? (raw[6] ~/ 1000) : 0); // nanos → µs
  }
  throw FormatException('Unsupported date format: $raw');
}

String? formatDate(DateTime? dt) => dt?.toIso8601String();