Policy Engine Interface

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;

interface IPolicyEngine {
    function isEligible(address subject, bytes calldata rule)
        external view returns (bool ok, uint32 reason);
}

Rule encoding example:

abi.encode(
    policyId,
    attestationUID,
    expectedEpochRoot,
    maxKycAge // e.g. 180 days
);