fix contract

contracts/ytLp/core/YTPriceFeed.sol

@@ -24,6 +24,7 @@ contract YTPriceFeed is Initializable, UUPSUpgradeable {
     error SpreadTooHigh();
     error InvalidAddress();
     error InvalidChainlinkPrice();
+    error StalePrice();
     
     address public gov;
     
@@ -35,6 +36,7 @@ contract YTPriceFeed is Initializable, UUPSUpgradeable {
     
     // 价格保护参数
     uint256 public maxPriceChangeBps; // 5% 最大价格变动
+    uint256 public priceStalenesThreshold; // 价格过期阈值（秒）
 
     /// @notice USDC价格Feed
     AggregatorV3Interface internal usdcPriceFeed;
@@ -72,6 +74,7 @@ contract YTPriceFeed is Initializable, UUPSUpgradeable {
         usdcPriceFeed = AggregatorV3Interface(_usdcPriceFeed);
         gov = msg.sender;
         maxPriceChangeBps = 500; // 5% 最大价格变动
+        priceStalenesThreshold = 3600; // 默认1小时
     }
 
     /**
@@ -116,6 +119,15 @@ contract YTPriceFeed is Initializable, UUPSUpgradeable {
         maxPriceChangeBps = _maxPriceChangeBps;
     }
     
+    /**
+     * @notice 设置价格过期阈值
+     * @param _threshold 阈值（秒），例如：3600 = 1小时，86400 = 24小时
+     */
+    function setPriceStalenessThreshold(uint256 _threshold) external onlyGov {
+        require(_threshold > 0 && _threshold <= 7 days, "Invalid threshold");
+        priceStalenesThreshold = _threshold;
+    }
+    
     /**
      * @notice 设置代币价差
      * @param _token 代币地址
@@ -220,15 +232,21 @@ contract YTPriceFeed is Initializable, UUPSUpgradeable {
      */
     function _getUSDCPrice() internal view returns (uint256) {
         (
-            /* uint80 roundId */,
+            uint80 roundId,
             int256 price,
             /* uint256 startedAt */,
-            /* uint256 updatedAt */,
-            /* uint80 answeredInRound */
+            uint256 updatedAt,
+            uint80 answeredInRound
         ) = usdcPriceFeed.latestRoundData();
         
+        // 价格有效性检查
         if (price <= 0) revert InvalidChainlinkPrice();
         
+        // 新鲜度检查：确保价格数据不过期
+        if (updatedAt == 0) revert StalePrice();
+        if (answeredInRound < roundId) revert StalePrice();
+        if (block.timestamp - updatedAt > priceStalenesThreshold) revert StalePrice();
+        
         return uint256(price) * 1e22; // 1e22 = 10^(30-8)
     }