Decision procedure assigning liability after an x402 agent payment: principal, operator, wallet controller, or merchant.

Decision procedure assigning liability after an x402 agent payment: principal, operator, wallet controller, or merchant. Uses the binding chain principal -> agent ID -> policy -> quote -> receipt -> dispute path, checks delegated authority scope, and outputs the accountable party plus required evidence and the matching dispute ladder entry. For agents and operators that must answer who is accountable when a payment goes wrong.