/// Raw local state payload and associated schema version.
class LocalDataRecord {
  const LocalDataRecord({required this.rawState, required this.schemaVersion});

  final String rawState;
  final int schemaVersion;
}

/// Persistence boundary for local app state.
abstract interface class LocalDataStore {
  /// Reads latest persisted state payload.
  Future<LocalDataRecord?> read();

  /// Writes state payload and schema version.
  Future<void> write({required String rawState, required int schemaVersion});

  /// Clears persisted state payload.
  Future<void> clear();
}