pragma solidity ^0.8.13;

contract CodeManifestRegistry {
    mapping(bytes32 => bytes32) private _manifests;

    event Registered(bytes32 indexed codeHash, bytes32 manifestRoot);

    function register(bytes32 manifestRoot) external {
        bytes32 codeHash = msg.sender.codehash;
        require(codeHash != bytes32(0), "EOA");
        bytes32 existing = _manifests[codeHash];
        require(existing == bytes32(0) || existing == manifestRoot, "exists");
        _manifests[codeHash] = manifestRoot;
        emit Registered(codeHash, manifestRoot);
    }

    function lookup(bytes32 codeHash) external view returns (bytes32) {
        return _manifests[codeHash];
    }
}