feat: prevent minting against node operator fee

Author: failingtwice

contracts/0.8.25/vaults/Dashboard.sol

@@ -166,11 +166,11 @@ contract Dashboard is Permissions {
     }
 
     /**
-     * @notice Returns the overall capacity of stETH shares that can be minted by the vault bound by valuation and vault share limit.
+     * @notice Returns the overall capacity of stETH shares that can be minted by the vault bound by valuation, unmintable valuation and vault share limit.
      * @return The maximum number of mintable stETH shares not counting already minted ones.
      */
     function totalMintableShares() public view returns (uint256) {
-        return _totalMintableShares(stakingVault().valuation());
+        return _totalMintableShares(stakingVault().valuation() - _unmintableValuation());
     }
 
     /**
@@ -179,7 +179,7 @@ contract Dashboard is Permissions {
      * @return the maximum number of shares that can be minted by ether
      */
     function projectedNewMintableShares(uint256 _etherToFund) external view returns (uint256) {
-        uint256 _totalShares = _totalMintableShares(stakingVault().valuation() + _etherToFund);
+        uint256 _totalShares = _totalMintableShares(stakingVault().valuation() + _etherToFund - _unmintableValuation());
         uint256 _sharesMinted = vaultSocket().sharesMinted;
 
         if (_totalShares < _sharesMinted) return 0;

contracts/0.8.25/vaults/Delegation.sol

@@ -217,6 +217,10 @@ contract Delegation is Dashboard {
         super._withdraw(_recipient, _ether);
     }
 
+    function _unmintableValuation() internal view override returns (uint256) {
+        return nodeOperatorUnclaimedFee();
+    }
+
     /**
      * @dev Emitted when the node operator fee is set.
      * @param oldNodeOperatorFeeBP The old node operator fee.

contracts/0.8.25/vaults/Permissions.sol

@@ -199,6 +199,7 @@ abstract contract Permissions is AccessControlConfirmable {
      */
     function _mintShares(address _recipient, uint256 _shares) internal onlyRole(MINT_ROLE) {
         vaultHub.mintShares(address(stakingVault()), _recipient, _shares);
+        _ensureUnmintableValuation();
     }
 
     /**
@@ -286,6 +287,19 @@ abstract contract Permissions is AccessControlConfirmable {
         }
     }
 
+    function _unmintableValuation() internal view virtual returns (uint256) {
+        return 0;
+    }
+
+    function _ensureUnmintableValuation() internal view {
+        uint256 locked = stakingVault().locked();
+        uint256 valuation = stakingVault().valuation();
+
+        if (locked > valuation - _unmintableValuation()) {
+            revert UnmintableValuationBreached(locked, valuation, _unmintableValuation());
+        }
+    }
+
     /**
      * @notice Emitted when the contract is initialized
      */
@@ -306,4 +320,9 @@ abstract contract Permissions is AccessControlConfirmable {
      * @param argument Name of the argument
      */
     error ZeroArgument(string argument);
+
+    /**
+     * @notice Error when unmintable valuation is breached
+     */
+    error UnmintableValuationBreached(uint256 locked, uint256 valuation, uint256 unmintableValuation);
 }