fix: new event for minimum delegation not met (TRST-M03)

Author: Maikol

packages/horizon/contracts/interfaces/internal/IHorizonStakingMain.sol

@@ -423,6 +423,13 @@ interface IHorizonStakingMain {
      */
     error HorizonStakingInvalidDelegationPool(address serviceProvider, address verifier);
 
+    /**
+     * @notice Thrown when the minimum token amount required for delegation is not met.
+     * @param tokens The actual token amount
+     * @param minTokens The minimum required token amount
+     */
+    error HorizonStakingInsufficientDelegationTokens(uint256 tokens, uint256 minTokens);
+
     /**
      * @notice Thrown when attempting to undelegate with a beneficiary that is the zero address.
      */

packages/horizon/contracts/staking/HorizonStaking.sol

@@ -869,7 +869,7 @@ contract HorizonStaking is HorizonStakingBase, IHorizonStakingMain {
     function _delegate(address _serviceProvider, address _verifier, uint256 _tokens, uint256 _minSharesOut) private {
         // Enforces a minimum delegation amount to prevent share manipulation attacks.
         // This stops attackers from inflating share value and blocking other delegators.
-        require(_tokens >= MIN_DELEGATION, HorizonStakingInsufficientTokens(_tokens, MIN_DELEGATION));
+        require(_tokens >= MIN_DELEGATION, HorizonStakingInsufficientDelegationTokens(_tokens, MIN_DELEGATION));
         require(
             _provisions[_serviceProvider][_verifier].createdAt != 0,
             HorizonStakingInvalidProvision(_serviceProvider, _verifier)

packages/horizon/test/staking/delegation/delegate.t.sol

@@ -67,7 +67,7 @@ contract HorizonStakingDelegateTest is HorizonStakingTest {
         vm.startPrank(users.delegator);
         token.approve(address(staking), delegationAmount);
         bytes memory expectedError = abi.encodeWithSelector(
-            IHorizonStakingMain.HorizonStakingInsufficientTokens.selector,
+            IHorizonStakingMain.HorizonStakingInsufficientDelegationTokens.selector,
             delegationAmount,
             MIN_DELEGATION
         );