基于可验证随机数的
哈希游戏

function fulfillRandomWords(
    uint256 requestId,
    uint256[] calldata randomWords
) internal override {
    // 1. 验证链上请求ID与当前奖池期号匹配
    require(s_requests[requestId].exists, "REQ_NOT_FOUND");
    
    // 2. 从VRF随机字数组中解构出主奖与特别号码
    uint256 winningSeed = randomWords[0];
    bytes32 drawHash = keccak256(abi.encodePacked(winningSeed, block.timestamp));
    
    // 3. 广播事件并由清算合约自动划拨派奖
    emit LotteryDrawn(s_currentRound, drawHash, block.number);
    _executePayoutPool(s_currentRound, drawHash);
}