refactor(swap-test): 抽取 TestableSwapEodPositionService 公共基类收敛重复 Stub

- 新建 TestableSwapEodPositionService 收敛 8/8 Stub 重复的高频 override
  (PersistEodSwapPosition/SaveAllChanges/GetCurrencyRate/AddClientCash)
  + 统一 OptUserInfo 构造 + PersistedPositions/SaveChangesCount 输出捕获
- SwapEodPositionService.DealInterests 改 protected virtual（行为零变化）
- 8 个 ScenarioTest 改为继承基类，删除重复 override
- 消灭 DealInterestsScenarioTest/DealInterestsGoldenReplayTest 的反射调用
  (typeof().GetMethod().Invoke → 直接调用 DealInterests)

验证：dotnet build 0 错误；dotnet test SwapModule 284通过/6跳过/0失败

UnitTestProject/Modules/SwapModule/ClearSwapPositionsScenarioTest.cs

@@ -21,7 +21,7 @@ namespace YLErp.Modules.SwapModule
 
         #region Stub
 
-        private sealed class StubService : SwapEodPositionService
+        private sealed class StubService : TestableSwapEodPositionService
         {
             // 注入的内存数据
             public List<swap_flow_event> FlowEvents { get; set; } = new();
@@ -30,7 +30,7 @@ namespace YLErp.Modules.SwapModule
 
             public List<ClientCashInCashOut> DeletedRecords { get; } = new();
 
-            public StubService() : base(new OptUserInfo(0, nameof(ClearSwapPositionsScenarioTest), OptUserFrom.UnitTest))
+            public StubService() : base(nameof(ClearSwapPositionsScenarioTest))
             {
             }