RegistrarController

1. makeCommitment(req)            → bytes32 commitment hash (pure, off-chain)
2. commit(commitment)             → stores timestamp on-chain
3. wait ≥ 60 seconds
4. register(req, paymentToken)   → mints name, sets resolver data, transfers NFT

struct RegisterRequest {
    string name;          // label only, e.g. "alice"
    bytes32 tld;          // namehash of TLD, e.g. namehash("web3")
    address owner;
    uint256 duration;     // seconds
    bytes32 secret;       // random 32 bytes
    address resolver;
    bytes[] resolverData; // encoded setAddr/setText calls
    bool reverseRecord;   // set reverse record at registration
}
 
// paymentToken: address(0) = ETH, USDC address = stablecoin
function register(RegisterRequest calldata req, address paymentToken) external payable;
function renew(string calldata name, bytes32 tld, uint256 duration, address paymentToken)
    external payable;
 
function makeCommitment(RegisterRequest calldata req) external pure returns (bytes32);
function commit(bytes32 commitment) external;
function rentPrice(string calldata name, bytes32 tld, uint256 duration)
    external view returns (uint256 base, uint256 premium);
function available(string calldata name, bytes32 tld) external view returns (bool);
 
// Owner only
function withdrawEth(address to) external;
function withdrawToken(address token, address to) external;
 
// Immutable
function USDC_TOKEN() external view returns (address);