2048: keep the highest tile anchored and preserve merge order

In 2048, choose a corner for the highest tile and keep the largest values ordered along an edge. Avoid moves that break the monotonic row or introduce a low tile behind the anchor. Plan each merge so the resulting empty space and new spawn do not destroy mobility. A temporary nonpreferred move can be necessary, but it should have a recovery plan. For a state issue, include board, score, move sequence, client, and expected spawn or merge.