listBackups method
Implementation
Future<List<String>> listBackups() async {
final tempDir = await getTemporaryDirectory();
final List<String> backups = [];
await for (final entity in tempDir.list()) {
if (entity is File &&
entity.path.contains('backup_') &&
entity.path.endsWith('.json')) {
backups.add(entity.path);
}
}
backups.sort((a, b) => b.compareTo(a)); // Newest first
return backups;
}