refactor(accrual): 抽取BuildSegmentRates共享分段取率+清理needPrice死参数

- 抽取 BuildSegmentRates：统一单利/复利分段取率循环，参数化 fetchAfterDate (单利传 ValueDate 仅取新段，复利传 null 全程取)

- 修复 BuildSegmentRates static→instance：访问实例属性 IndexFixer

- 清理 CalcDaily 层 needPrice 死参数：4个 CalcDaily* 方法签名移除 needPrice；上层 CalcSwapInterests/GetInterests 保留 (virtual seam/位置参数兼容)

- 修复 6 处调用点 needPrice 参数传递

- 新增影子测试：单利+FR007浮动+部分平仓+历史归档，验证 segmentRates 一致

- 新增 TdCarryInCharacterizationTest：钉死部分平仓 TdInterestAmount carry-in 行为

测试: 511通过 / 7预存在失败(数据依赖) / 9跳过

UnitTestProject/Modules/SwapModule/Accrual/SimplePeriodShadowTest.cs

@@ -100,7 +100,7 @@ namespace UnitTestProject.Modules.SwapModule.Accrual
             decimal oldI = 0, oldTd = 0;
             var svc = new StubSvc();
             svc.CalcDailySimpleInterest(preEod, EndDate, position, Notional, flowEvent,
-                AnnualDays, false, 0m, 1m, Notional, true, false, ref oldI, ref oldTd);
+                AnnualDays, 0m, 1m, Notional, true, false, ref oldI, ref oldTd);
 
             // 新方法：固定利率全段相同
             // 旧代码差分: dynomicPrincipal = preEod.TdInterestPrincipal(=0) + posiPrincipal - orginPv = 0
@@ -146,7 +146,7 @@ namespace UnitTestProject.Modules.SwapModule.Accrual
             decimal oldI = 0, oldTd = 0;
             var svc = new StubSvc();
             svc.CalcDailySimpleInterest(preEod, EndDate, position, Notional, flowEvent,
-                AnnualDays, false, 0m, 0.5m, Notional, true, false, ref oldI, ref oldTd);
+                AnnualDays, 0m, 0.5m, Notional, true, false, ref oldI, ref oldTd);
 
             // 新方法
             // 差分本金 = preEod.TdInterestPrincipal + posiPrincipal - orginPv
@@ -200,7 +200,7 @@ namespace UnitTestProject.Modules.SwapModule.Accrual
             decimal oldI = 0, oldTd = 0;
             var svc = new FloatStubSvc(new StubIndexFixer(fixingAtReset));
             svc.CalcDailySimpleInterest(preEod, EndDate, position, Notional, flowEvent,
-                AnnualDays, false, floatRateIn, closePct, Notional, true, false, ref oldI, ref oldTd);
+                AnnualDays, floatRateIn, closePct, Notional, true, false, ref oldI, ref oldTd);
 
             // 新方法：手算 segmentRates（对齐旧代码取价循环的逻辑）
             // 4/21 <= preEodDate(4/30) → 跳过取价，currentFloat 保持入参 floatRateIn