change WUSD payment to USDC

contracts/ytLp/tokens/WUSD.sol

@@ -1,59 +0,0 @@
-// SPDX-License-Identifier: MIT
-pragma solidity ^0.8.0;
-
-import "@openzeppelin/contracts-upgradeable/token/ERC20/ERC20Upgradeable.sol";
-import "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";
-import "@openzeppelin/contracts-upgradeable/proxy/utils/UUPSUpgradeable.sol";
-import "@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol";
-
-/**
- * @title WUSD
- * @notice Wrapped USD - 简单的ERC20代币
- */
-contract WUSD is Initializable, ERC20Upgradeable, UUPSUpgradeable, OwnableUpgradeable {
-    
-    /// @custom:oz-upgrades-unsafe-allow constructor
-    constructor() {
-        _disableInitializers();
-    }
-    
-    /**
-     * @notice 初始化合约
-     * @param _name 代币名称
-     * @param _symbol 代币符号
-     */
-    function initialize(string memory _name, string memory _symbol) external initializer {
-        __ERC20_init(_name, _symbol);
-        __UUPSUpgradeable_init();
-        __Ownable_init(msg.sender);
-    }
-    
-    /**
-     * @notice 授权升级（仅owner可调用）
-     * @param newImplementation 新实现合约地址
-     */
-    function _authorizeUpgrade(address newImplementation) internal override onlyOwner {}
-    
-    /**
-     * @notice 铸造代币
-     * @param _to 接收地址
-     * @param _amount 铸造数量
-     */
-    function mint(address _to, uint256 _amount) external onlyOwner {
-        _mint(_to, _amount);
-    }
-    
-    /**
-     * @notice 销毁代币
-     * @param _from 销毁地址
-     * @param _amount 销毁数量
-     */
-    function burn(address _from, uint256 _amount) external onlyOwner {
-        _burn(_from, _amount);
-    }
-    
-    /**
-     * @dev 预留存储空间，用于未来升级时添加新的状态变量
-     */
-    uint256[50] private __gap;
-}