feat: ExecutorTransferMethods helper contract

- Also sketch its use in USV2 (missing proper decoding)

foundry/src/executors/ExecutorTransferMethods.sol

@@ -0,0 +1,52 @@
+// SPDX-License-Identifier: BUSL-1.1
+pragma solidity ^0.8.26;
+
+import "@interfaces/IExecutor.sol";
+import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
+import "@permit2/src/interfaces/IAllowanceTransfer.sol";
+import "@permit2/src/interfaces/IAllowanceTransfer.sol";
+
+error ExecutorTransferMethods__InvalidPermit2();
+
+contract ExecutorTransferMethods {
+    using SafeERC20 for IERC20;
+
+    IAllowanceTransfer public immutable permit2;
+
+    enum TransferMethod {
+        TRANSFER,
+        TRANSFERFROM,
+        TRANSFERPERMIT2,
+        NONE
+    }
+
+    constructor(address _permit2) {
+        if (_permit2 == address(0)) {
+            revert ExecutorTransferMethods__InvalidPermit2();
+        }
+        permit2 = IAllowanceTransfer(_permit2);
+    }
+
+    function _transfer(
+        IERC20 tokenIn,
+        address receiver,
+        uint256 amount,
+        TransferMethod method
+    ) internal {
+        if (method == TransferMethod.TRANSFER) {
+            tokenIn.safeTransfer(receiver, amount);
+        } else if (method == TransferMethod.TRANSFERFROM) {
+            tokenIn.safeTransferFrom(msg.sender, receiver, amount);
+        } else if (method == TransferMethod.TRANSFERPERMIT2) {
+            // Permit2.permit is called from the TychoRouter
+            permit2.transferFrom(
+                msg.sender,
+                receiver, // Does this work if receiver is not address(this)?
+                uint160(amount),
+                address(tokenIn)
+            );
+        } else {
+            // Funds are likely already in pool. Do nothing.
+        }
+    }
+}