suggestMove method
The move the hard bot would play now, for showing a hint to a human.
null unless a piece selection is pending.
Implementation
LudoLegalMove? suggestMove() {
if (_state.phase != LudoTurnPhase.awaitingPieceSelection ||
_state.legalMoves.isEmpty) {
return null;
}
return const LudoHardBot().chooseMove(_state);
}