refactor(swap): Phase1 提取UnwindNormalizer+TradingFeeCalc出SwapDealService

SwapDealService的10个private static纯逻辑方法搬到两个新文件:
- UnwindNormalizer.cs: NormalizeNotionalValues/FullCloseRequest/Recalculate/IsFullClose/SettledInterestAmounts/EventUnwindDate (6个)
- TradingFeeCalc.cs: CalcInitTradingFee/CalcInitTradingFeePending (2个)

SwapDealService内21处调用点加类名前缀, 反射测试改为直接调用(public)
SwapModule零回归(7基线/510通过)

UnitTestProject/Modules/SwapModule/InitUnwindTradingFeeTest.cs

@@ -1,4 +1,3 @@
-using System.Reflection;
 using YLErp.DBModels;
 
 namespace YLErp.Modules.SwapModule
@@ -7,26 +6,10 @@ namespace YLErp.Modules.SwapModule
     public class InitUnwindTradingFeeTest
     {
         private static decimal InvokeCalcInitTradingFee(swap_position position, UnwindData unwindData)
-        {
-            var method = typeof(SwapDealService).GetMethod(
-                "CalcInitTradingFee",
-                BindingFlags.NonPublic | BindingFlags.Static);
-
-            Assert.IsNotNull(method, "未找到 CalcInitTradingFee 私有静态方法");
-
-            return (decimal)method.Invoke(null, new object[] { position, unwindData });
-        }
+            => TradingFeeCalc.CalcInitTradingFee(position, unwindData);
 
         private static decimal InvokeCalcInitTradingFeePending(swap_position oriPosition, swap_position position, UnwindData unwindData)
-        {
-            var method = typeof(SwapDealService).GetMethod(
-                "CalcInitTradingFeePending",
-                BindingFlags.NonPublic | BindingFlags.Static);
-
-            Assert.IsNotNull(method, "CalcInitTradingFeePending was not found");
-
-            return (decimal)method.Invoke(null, new object[] { oriPosition, position, unwindData });
-        }
+            => TradingFeeCalc.CalcInitTradingFeePending(oriPosition, position, unwindData);
 
         [TestMethod]
         public void 百分比模式_按平仓名义本金计算并四舍五入到两位()