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/ComposePageScenarioTest.cs

@@ -22,13 +22,13 @@ namespace YLErp.Modules.SwapModule
 
         #region Stub
 
-        private sealed class StubEodService : SwapEodPositionService
+        private sealed class StubEodService : TestableSwapEodPositionService
         {
-            public List<eod_swap_position> CreatedEodPositions { get; } = new();
-            public int ClientCashCallCount { get; private set; }
-            private int _nextId = 1;
+            // 输出别名（转发到基类捕获属性，保持测试断言不变）
+            public List<eod_swap_position> CreatedEodPositions => PersistedPositions;
+            public int ClientCashCallCount => ClientCashCalls.Count;
 
-            public StubEodService() : base(new OptUserInfo(0, nameof(ComposePageScenarioTest), OptUserFrom.UnitTest))
+            public StubEodService() : base(nameof(ComposePageScenarioTest))
             {
             }
 
@@ -56,13 +56,7 @@ namespace YLErp.Modules.SwapModule
 
             protected override swap_event AddSwapEvent(DateTime tradeDate, int swapTradeId, int eventType, string data, int clientCashId, bool save, string reason)
             {
-                return new swap_event { id = _nextId++, SwapTradeId = swapTradeId, EventType = eventType, ValueDate = tradeDate, EventData = data };
-            }
-
-            protected override int AddClientCash(trade td, double amount, string action, DateTime valueDate)
-            {
-                ClientCashCallCount++;
-                return _nextId++;
+                return new swap_event { id = 1, SwapTradeId = swapTradeId, EventType = eventType, ValueDate = tradeDate, EventData = data };
             }
 
             protected override void SaveEodSwapRecord(trade td, DateTime settleDate, DateTime preSettleDate)
@@ -75,17 +69,6 @@ namespace YLErp.Modules.SwapModule
                 // 不做任何事（测试无历史事件需清理）
             }
 
-            protected override void PersistEodSwapPosition(eod_swap_position position)
-            {
-                if (position.id == 0) position.id = _nextId++;
-                CreatedEodPositions.Add(position);
-            }
-
-            protected override void SaveAllChanges() { }
-
-            protected override double GetCurrencyRate(string quoteCurrency, string settlementCurrency, DateTime valueDate, bool seekPreday, CurrencyRateType currencyRateType)
-                => 1.0;
-
             // override SaveEodPosition：捕获生成的 eod，绕过 UpdateSwapPosition 连库
             protected override decimal SaveEodPosition(eod_swap_position newEodPayPosition,
                 trade td, swap_flow_event eventFlow,