fix(swap): 修复部分平仓后复利本金计算逻辑(修复T+1)

- 修复部分平仓后下一日复利本金未按剩余比例继承的问题
- 添加对最终日不算尾时历史差分重放的日期边界控制
- 修复算头不算尾快速路径中已平部分进入下一日复利的错误
- 确保重置日动态本金不会被二次缩放导致剩余本金计算错误
- 添加单元测试验证部分平仓后复利本金按剩余70%本金计提的逻辑
- 补充最终全平重放时历史终点包含当日利息后再做差额的测试用例

UnitTestProject/Modules/SwapModule/DealInterestsScenarioTest.cs

@@ -1562,6 +1562,9 @@ namespace YLErp.Modules.SwapModule
                 "0005 计算不算尾时，部分平仓日终新增复利必须按剩余70%本金计提");
             AssertDecimal(196212.213529615939m, partialEod.InterestIncomeSum,
                 "0005 部分平仓后日终待实现复利必须扣除实际80002.30结算");
+            AssertDecimal(previousEod.TdInterestPrincipal * (1m - partialNotional / originalNotional),
+                partialEod.TdInterestPrincipal,
+                "0005 部分平仓后，下一日复利本金必须只继承剩余70%本金");
 
             var intermediateDate = new DateTime(2026, 5, 18);
             var intermediateInterest = dealService.GetInterests(
@@ -1573,6 +1576,39 @@ namespace YLErp.Modules.SwapModule
             Assert.IsTrue(Math.Abs(259348.386714765m - intermediateInterest.InterestAmount) <= 0.01m,
                 $"0005 5/18 复利应承接部分平仓后的累计利息 Expected approximately 259348.386714765, Actual: {intermediateInterest.InterestAmount}");
 
+            var intermediateEod = partialEod.Clone();
+            intermediateEod.id = 18283;
+            intermediateEod.ValueDate = intermediateDate;
+            intermediateEod.InterestIncomeSum = intermediateInterest.InterestAmount;
+            intermediateEod.InterestProfitSum = intermediateInterest.InterestAmount;
+            intermediateEod.TdInterestPrincipal = remainingNotional;
+            intermediateEod.PosiNotionalValue = remainingNotional;
+
+            var expectedEndFlow = new swap_flow_event { InterestRate = spread };
+            decimal expectedAmountAtEnd = 0m;
+            decimal expectedTdAmountAtEnd = 0m;
+            dealService.CalcDailyCompoundInterest(
+                finalCloseDate, position, remainingNotional, expectedEndFlow, AnnualDays, false,
+                intermediateEod.FloatRate, 1m, originalNotional, true, false,
+                ref expectedAmountAtEnd, ref expectedTdAmountAtEnd);
+            var expectedPreviousFlow = new swap_flow_event { InterestRate = spread };
+            decimal expectedAmountAtPreviousEod = 0m;
+            decimal expectedTdAmountAtPreviousEod = 0m;
+            dealService.CalcDailyCompoundInterest(
+                intermediateDate, position, remainingNotional, expectedPreviousFlow, AnnualDays, false,
+                intermediateEod.FloatRate, 1m, originalNotional, true, true,
+                ref expectedAmountAtPreviousEod, ref expectedTdAmountAtPreviousEod);
+            var expectedFinalInterest = intermediateEod.InterestIncomeSum
+                + expectedAmountAtEnd - expectedAmountAtPreviousEod;
+            var finalInterest = dealService.GetInterests(
+                td, td.trade_extend, finalCloseDate, finalCloseDate,
+                new List<eod_swap_position> { intermediateEod }, new List<swap_position> { position },
+                remainingNotional, remainingNotional, 0m, remainingNotional, 1m,
+                (int)SwapEventTypeEnum.平仓, false, false, 0m, originalNotional,
+                settment: false, newCalcLast: false).Single();
+            AssertDecimal(expectedFinalInterest, finalInterest.InterestAmount,
+                "0005 最终全平重放时，历史5/18终点必须包含当日利息后再做差额");
+
         }
 
         [TestMethod]