Contract 9.10.0

battles_deck_sets takes exclude_decks: deck_hash values no set may choose (any variant names the same eight cards; candidates.excluded_decks counts them), so "a different last war deck" is the other three locked and the current fourth excluded. Read back through a clan's agent at 9.9.1, the search free to choose any fourth deck chose the one the player already plays, and the agent offered it as new.