fix: guard against currentStake exceeding SortitionModuleNeo.maxStakePerJuror

Author: jaybuidl

contracts/src/arbitration/SortitionModuleNeo.sol

@@ -85,7 +85,7 @@ contract SortitionModuleNeo is SortitionModuleBase {
         uint256 stakeChange = stakeIncrease ? _newStake - currentStake : currentStake - _newStake;
         Juror storage juror = jurors[_account];
         if (stakeIncrease) {
-            if (juror.stakedPnk + stakeChange > maxStakePerJuror) {
+            if (juror.stakedPnk + stakeChange > maxStakePerJuror || currentStake + stakeChange > maxStakePerJuror) {
                 return (0, 0, StakingResult.CannotStakeMoreThanMaxStakePerJuror);
             }
             if (totalStaked + stakeChange > maxTotalStaked) {

contracts/src/libraries/Constants.sol

@@ -9,7 +9,7 @@ uint96 constant FORKING_COURT = 0; // Index of the forking court.
 uint96 constant GENERAL_COURT = 1; // Index of the default (general) court.
 
 // Dispute Kits
-uint256 constant NULL_DISPUTE_KIT = 0; // Null pattern to indicate a top-level DK which has no parent. DEPRECATED, as its main purpose was to accommodate forest structure which is not used now.
+uint256 constant NULL_DISPUTE_KIT = 0; // Null pattern to indicate a top-level DK which has no parent.
 uint256 constant DISPUTE_KIT_CLASSIC = 1; // Index of the default DK. 0 index is skipped.
 
 // Sortition Module