Refactor ETH balance and gas fee checks in SpotBot

- Updated balance checks to utilize user-defined thresholds for minimum trading and swap balances, enhancing flexibility.
- Improved gas fee validation by incorporating user settings, allowing for more personalized transaction management.
- Enhanced logging to provide clearer messages regarding balance sufficiency and gas fee limits, improving user feedback during operations.

src/Managing.Application/Trading/Handlers/OpenPositionCommandHandler.cs

@@ -51,10 +51,13 @@ namespace Managing.Application.Trading.Handlers
                 if (account.Exchange == TradingExchanges.Evm || account.Exchange == TradingExchanges.GmxV2)
                 {
                     var currentGasFees = await exchangeService.GetFee(account);
-                    if (currentGasFees > Constants.GMX.Config.MaximumGasFeeUsd)
+                    // Use user's max gas fee setting, fallback to default constant
+                    var maxGasFeeThreshold = request.User.MaxTxnGasFeePerPosition ?? Constants.GMX.Config.MaximumGasFeeUsd;
+                    
+                    if (currentGasFees > maxGasFeeThreshold)
                     {
                         throw new InsufficientFundsException(
-                            $"Gas fee too high for position opening: {currentGasFees:F2} USD (threshold: {Constants.GMX.Config.MaximumGasFeeUsd} USD). Position opening rejected.",
+                            $"Gas fee too high for position opening: {currentGasFees:F2} USD (threshold: {maxGasFeeThreshold:F2} USD). Position opening rejected.",
                             InsufficientFundsType.HighNetworkFee);
                     }
                 }