3214386556
FenParser.parseFen now returns Either[String, GameContext] instead of Option. Updated all tests to use Either combinators (isRight, isLeft, fold) instead of Option methods (isDefined, get). Both FenParserTest and FenExporterTest now properly handle the Either-based return type. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>