fix(swap): 修复复利计算中的利息处理逻辑

- 添加了从开始日期到结束日期的天数计算
- 添加了从前一日末到结束日期的天数计算
- 修复了特定条件下利息本金和浮动利率的赋值
- 修正了利息金额和累计利息金额的计算
- 添加了四舍五入处理以确保精度准确性
- 修复了利息平仓损益的计算逻辑

YLErpDAL/Modules/SwapModule/SwapDealService.cs

@@ -1205,6 +1205,21 @@ namespace YLErp.Modules.SwapModule
                 var floateRate = preEodPosition.FloatRate;
                 if (position.InterestType == (int)InterestTypeEnum.复利)
                 {
+                    var daysFromStart = (endDate - position.PosiStartDate).Days;
+                    var daysFromPreEod = preEodPosition.id != 0
+                        ? (endDate - preEodPosition.ValueDate).Days
+                        : 0;
+                    if (!calcLast && daysFromPreEod == 1 && daysFromStart % (position.interest_rest_days ?? 1) != 0)
+                    {
+                        interest.InterestPrincipal = preEodPosition.TdInterestPrincipal * closePrecent;
+                        interest.FloatRate = preEodPosition.FloatRate;
+                        InterestAmount = preEodPosition.InterestIncomeSum * closePrecent;
+                        TdInterestAmount = preEodPosition.InterestIncomeSum;
+                        interest.InterestAmount = Math.Round(InterestAmount, InterestCalculationPrecision, MidpointRounding.AwayFromZero);
+                        interest.TdInterestAmount = Math.Round(TdInterestAmount, InterestCalculationPrecision, MidpointRounding.AwayFromZero);
+                        interest.InterestClosePnL = interest.InterestAmount * interestRatio;
+                        return interest;
+                    }
                     var remainingPercent = preEodPosition.TdInterestPrincipal > 0m
                         ? closePosiNotionalValue / preEodPosition.TdInterestPrincipal
                         : 1m;