feat: pull in required vendor dependencies

.gitmodules

@@ -1,3 +1,12 @@
 [submodule "lib/forge-std"]
 	path = lib/forge-std
 	url = https://github.com/foundry-rs/forge-std
+[submodule "lib/cow"]
+	path = lib/cow
+	url = https://github.com/cowprotocol/contracts
+[submodule "lib/euler-vault-kit"]
+	path = lib/euler-vault-kit
+	url = https://github.com/euler-xyz/euler-vault-kit
+[submodule "lib/evc"]
+	path = lib/evc
+	url = https://github.com/euler-xyz/ethereum-vault-connector

foundry.lock

@@ -1,4 +1,10 @@
 {
+  "lib/cow": {
+    "rev": "39d7f4d68e37d14adeaf3c0caca30ea5c1a2fad9"
+  },
+  "lib/euler-vault-kit": {
+    "rev": "5b98b42048ba11ae82fb62dfec06d1010c8e41e6"
+  },
   "lib/forge-std": {
     "tag": {
       "name": "v1.10.0",

remappings.txt

@@ -0,0 +1,4 @@
+cow/=lib/cow/src/contracts
+evc/=lib/euler-vault-kit/lib/ethereum-vault-connector/src/
+ethereum-vault-connector/=lib/euler-vault-kit/lib/ethereum-vault-connector/src/
+openzeppelin/=lib/euler-vault-kit/lib/ethereum-vault-connector/lib/openzeppelin-contracts/contracts/

src/vendor/interfaces/IERC20.sol

@@ -0,0 +1,112 @@
+// SPDX-License-Identifier: MIT
+
+// Vendored from OpenZeppelin contracts with minor modifications:
+// - Modified Solidity version
+// - Formatted code
+// - Added `name`, `symbol` and `decimals` function declarations
+// <https://github.com/OpenZeppelin/openzeppelin-contracts/blob/v3.4.0/contracts/token/ERC20/IERC20.sol>
+
+pragma solidity ^0.8;
+
+/**
+ * @dev Interface of the ERC20 standard as defined in the EIP.
+ */
+interface IERC20 {
+    /**
+     * @dev Returns the name of the token.
+     */
+    function name() external view returns (string memory);
+
+    /**
+     * @dev Returns the symbol of the token.
+     */
+    function symbol() external view returns (string memory);
+
+    /**
+     * @dev Returns the number of decimals the token uses.
+     */
+    function decimals() external view returns (uint8);
+
+    /**
+     * @dev Returns the amount of tokens in existence.
+     */
+    function totalSupply() external view returns (uint256);
+
+    /**
+     * @dev Returns the amount of tokens owned by `account`.
+     */
+    function balanceOf(address account) external view returns (uint256);
+
+    /**
+     * @dev Moves `amount` tokens from the caller's account to `recipient`.
+     *
+     * Returns a boolean value indicating whether the operation succeeded.
+     *
+     * Emits a {Transfer} event.
+     */
+    function transfer(
+        address recipient,
+        uint256 amount
+    ) external returns (bool);
+
+    /**
+     * @dev Returns the remaining number of tokens that `spender` will be
+     * allowed to spend on behalf of `owner` through {transferFrom}. This is
+     * zero by default.
+     *
+     * This value changes when {approve} or {transferFrom} are called.
+     */
+    function allowance(
+        address owner,
+        address spender
+    ) external view returns (uint256);
+
+    /**
+     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
+     *
+     * Returns a boolean value indicating whether the operation succeeded.
+     *
+     * IMPORTANT: Beware that changing an allowance with this method brings the risk
+     * that someone may use both the old and the new allowance by unfortunate
+     * transaction ordering. One possible solution to mitigate this race
+     * condition is to first reduce the spender's allowance to 0 and set the
+     * desired value afterwards:
+     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
+     *
+     * Emits an {Approval} event.
+     */
+    function approve(address spender, uint256 amount) external returns (bool);
+
+    /**
+     * @dev Moves `amount` tokens from `sender` to `recipient` using the
+     * allowance mechanism. `amount` is then deducted from the caller's
+     * allowance.
+     *
+     * Returns a boolean value indicating whether the operation succeeded.
+     *
+     * Emits a {Transfer} event.
+     */
+    function transferFrom(
+        address sender,
+        address recipient,
+        uint256 amount
+    ) external returns (bool);
+
+    /**
+     * @dev Emitted when `value` tokens are moved from one account (`from`) to
+     * another (`to`).
+     *
+     * Note that `value` may be zero.
+     */
+    event Transfer(address indexed from, address indexed to, uint256 value);
+
+    /**
+     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
+     * a call to {approve}. `value` is the new allowance.
+     */
+    event Approval(
+        address indexed owner,
+        address indexed spender,
+        uint256 value
+    );
+}