chore: forgelint and reduce size

Author: Filipp Makarov

contracts/nexus/Nexus.sol

@@ -358,7 +358,12 @@ contract Nexus is INexus, BaseAccount, ExecutionHelper, ModuleManager, UUPSUpgra
                 // Remove the signature  from the initData
                 initData = initData[65:];
                 // Calculate the hash of the initData
-                bytes32 initDataHash = keccak256(initData);
+                bytes32 initDataHash;
+                assembly {
+                    let ptr := mload(0x40)
+                    calldatacopy(ptr, initData.offset, initData.length)
+                    initDataHash := keccak256(ptr, initData.length)
+                }
                 // Make sure the account has not been already initialized
                 // Means relay can not re-initialize the account
                 require(!isInitialized(), AccountAlreadyInitialized());
@@ -412,7 +417,7 @@ contract Nexus is INexus, BaseAccount, ExecutionHelper, ModuleManager, UUPSUpgra
         // Handle potential ERC7739 support detection request
         if (signature.length == 0) {
             // Forces the compiler to optimize for smaller bytecode size.
-            /// forge-lint:disable-next-line(divide-before-multiplModuleManager.sol:716:16y)
+            /// forge-lint:disable-next-line(divide-before-multiply)
             if (uint256(hash) == (~signature.length / 0xffff) * 0x7739) {
                 return _checkERC7739Support(hash, signature);
             }

contracts/nexus/base/ModuleManager.sol

@@ -713,7 +713,25 @@ abstract contract ModuleManager is Storage, EIP712, IModuleManager {
         pure
         returns (bytes32)
     {
-        return keccak256(abi.encode(MODULE_ENABLE_MODE_TYPE_HASH, module, moduleType, userOpHash, keccak256(initData)));
+        bytes32 structHash;
+        assembly {
+            let ptr := mload(0x40)
+            mstore(ptr, MODULE_ENABLE_MODE_TYPE_HASH)
+            mstore(add(ptr, 0x20), module)
+            mstore(add(ptr, 0x40), moduleType)
+            mstore(add(ptr, 0x60), userOpHash)
+
+            // Hash initData and store at ptr + 0x80
+            // calldatacopy to copy initData to memory, then hash it
+            let initDataPtr := add(ptr, 0xa0)
+            calldatacopy(initDataPtr, initData.offset, initData.length)
+            let initDataHash := keccak256(initDataPtr, initData.length)
+            mstore(add(ptr, 0x80), initDataHash)
+
+            // Hash the entire struct
+            structHash := keccak256(ptr, 0xa0)
+        }
+        return structHash;
     }
 
     function _fallback(bytes calldata callData) private {