Require every new seat's bond to be CO-STAKED: an already-established agent must lock its own capital beside the newcomer's, and that backer is slashed too if the identity cheats. A farmer has no established backer willing to burn real stake on a grove of fakes, so each unbacked clone carries zero weight, the orchard only bears fruit where a real agent risked capital. Honest newcomers find one sponsor; a thousand sybils would need a thousand onyx-hard co-stakes nobody posts, so the smallest ember of fraud becomes the backer's loss too.