read method
override
Reads tokens from secure storage.
Implementation
@override
/// Reads tokens from secure storage.
Future<TokenPair?> read() async {
final access = await _storage.read(key: _kAccess);
final refresh = await _storage.read(key: _kRefresh);
if (access == null || refresh == null) return null;
return TokenPair(accessToken: access, refreshToken: refresh);
}