moveStakeToSelfStake Does Not Decrease stakers Count

When a user transfers their PoolOwnership NFT by calling transferFrom(), the NFT contract internally invokes:

function moveStakeToSelfStake(address staker) public {
    require(msg.sender == address(ownershipNFT), "Only NFT contract can call");
    if (stakes[staker] > 0) {
        selfStake += stakes[staker];
        stakes[staker] = 0;
    }
}

While the function correctly transfers the user's stake into selfStake and clears the user's individual stake record, it does not decrement the stakers counter, which is used to track the number of unique addresses with a non-zero stake.

As a result, if a user holding stake transfers their ownership NFT, their stake is zeroed out, but the system still counts them as an active staker.

• The stakers variable becomes inaccurate, reflecting a higher count than the actual number of unique stakers.
• This can affect analytics, on-chain or off-chain reward calculations, frontend representations, and any logic relying on the true count of active stakers.

The stakers counter drifts upward over time, breaking analytics and any feature that relies on accurate staker counts.

Update the moveStakeToSelfStake function to ensure the stakers count is decremented when a non-zero stake is moved:

function moveStakeToSelfStake(address staker) public {
    require(msg.sender == address(ownershipNFT), "Only NFT contract can call");
    if (stakes[staker] > 0) {
        selfStake += stakes[staker];
        stakes[staker] = 0;
        stakers--; // Adjust stakers count accurately
    }
}