Wrong rounding direction in StakingPool::unstake() can be abused

function unstake(uint256 amount) external {
    ...

    // Get current units and calculate units to remove proportionally
    // This maintains the exact proportional relationship between units and staked amount
    uint128 currentUnits = distributionPool.getUnits(msg.sender);
    uint128 unitsToRemove = uint128((amount * currentUnits) / userStakingInfo.stakedAmount);

    // Update member units
    distributionPool.decreaseMemberUnits(msg.sender, unitsToRemove);

    // Update staking info
    _stakingInfo[msg.sender].stakedAmount -= amount;

    // If all tokens are unstaked, reset the staking info
    if (_stakingInfo[msg.sender].stakedAmount == 0) {
        delete _stakingInfo[msg.sender];
    }

    // Transfer staked tokens back to user
    child.transfer(msg.sender, amount);

    emit Unstaked(msg.sender, amount);
}