test(swap): 补ApproveSwapTrade/ApplySwapTrade测试+3个seam(借鉴testable分支)

借鉴 origin/glms/feature/refactor-swap-event-testable 的 SwapUnwindScenarioTest 场景4/5,
补全当前分支缺失的平仓审批流程覆盖。

SwapDealService 新增3个 protected virtual seam:
- FindSwapEvent(查待审核事件)
- FindFlowEventsByEventId(查事件关联流水)
- CloseReCheckSetTrade(前置校验包装)
ApproveSwapTrade/ApplySwapTrade 重构为调seam,生产行为不变。

SwapDealSettlementTest 新增2个测试(SD_005/006,共6个):
- SD_005 ApproveSwapTrade 全平仓审核: 反序列化swap_event.EventData→资金流水→TradeStatus
- SD_006 ApplySwapTrade 提交审核: CloseReCheck前置校验+SwapRealizedPnL=SwapCloseAmount

融合策略: 保留当前分支SwapIncome资金流水断言独特价值(SD_001/002),
借鉴testable分支审批流程覆盖(SD_005/006),不二选一。
SwapModule 157测试全绿,无回归。

YLErpDAL/Modules/SwapModule/SwapDealService.cs

@@ -95,6 +95,26 @@ namespace YLErp.Modules.SwapModule
             });
         }
 
+        /// <summary>查找待审核的互换/平仓事件（生产: DbContext.swap_event 查询；测试: 返回内存对象）</summary>
+        protected virtual swap_event FindSwapEvent(int tradeId, int eventType)
+        {
+            return DbContext.swap_event
+                .Where(x => x.SwapTradeId == tradeId && !x.Invalid && x.EventType == eventType)
+                .OrderByDescending(o => o.id).FirstOrDefault();
+        }
+
+        /// <summary>查找事件关联的流水事件（生产: DbContext.swap_flow_event 查询；测试: 返回内存列表）</summary>
+        protected virtual List<swap_flow_event> FindFlowEventsByEventId(long eventId)
+        {
+            return DbContext.swap_flow_event.Where(x => x.EventId == eventId).ToList();
+        }
+
+        /// <summary>平仓/互换审核的前置校验与状态设置（生产: new TradeUnwindService；测试: 空操作或计数）</summary>
+        protected virtual void CloseReCheckSetTrade(int swapTradeId, bool isSwap, bool needCheck)
+        {
+            new TradeUnwindService(this).CloseReCheck_SetTrade(swapTradeId, isSwap, needCheck);
+        }
+
         #endregion
 
         public SwapDealService(OptUserInfo optUser) : base(optUser)
@@ -1578,14 +1598,13 @@ namespace YLErp.Modules.SwapModule
         /// <exception cref="Exception"></exception>
         public void ApproveSwapTrade(trade td, int eventType)
         {
-            Expression<Func<swap_event, bool>> eventExpression = x => x.SwapTradeId == td.id && !x.Invalid && x.EventType == eventType;
-            var swapEvent = DbContext.swap_event.Where(eventExpression).OrderByDescending(o => o.id).FirstOrDefault();
+            var swapEvent = FindSwapEvent(td.id, eventType);
             if (swapEvent == null)
             {
                 throw new Exception("该笔交易状态为平仓待复核，未找到相关记录，请检查该笔交易是否有效");
             }
             swapEvent.unwindData = JsonConvert.DeserializeObject<UnwindData>(swapEvent.EventData);
-            var flowList = DbContext.swap_flow_event.Where(x => x.EventId == swapEvent.id).ToList();
+            var flowList = FindFlowEventsByEventId(swapEvent.id);
             string action = eventType == (int)SwapEventTypeEnum.互换 ? ClientCashInCashOut.系统操作_互换 : ClientCashInCashOut.系统操作_平仓费;
             int clientCashId = AddClientCash(td, Convert.ToDouble(-swapEvent.unwindData.SwapRealizedPnL), action, swapEvent.unwindData.ValueDate);
             if (swapEvent.unwindData.SwapMarginAmount != 0)
@@ -1605,14 +1624,14 @@ namespace YLErp.Modules.SwapModule
             }
             td.UnWindDate = swapEvent.unwindData.UnwindDate;
             if (eventType != (int)SwapEventTypeEnum.互换)
-            {   
+            {
                 td.StockEqvNotional -= Convert.ToDouble(swapEvent.unwindData.CloseNotionalValue);
                 td.TradeAmount -= Convert.ToDouble(swapEvent.unwindData.CloseQty);
             }
 
             td.Notional = td.TradeAmount;
             UpdateInitalPosition(flowList, swapEvent.unwindData, eventType);
-            DbContext.SaveChanges();
+            SaveAllChanges();
 
         }
         /// <summary>
@@ -1623,30 +1642,19 @@ namespace YLErp.Modules.SwapModule
         /// <exception cref="ServiceException"></exception>
         public void ApplySwapTrade(UnwindData unwindData, int eventType)
         {
-            var td = DbContext.trade.Find(unwindData.SwapTradeId);
+            var td = FindTrade(unwindData.SwapTradeId);
             if (td == null)
             {
                 throw new ServiceException("未找到交易信息");
             }
             unwindData.SwapRealizedPnL = unwindData.SwapCloseAmount;
-            var trans = DbContext.Database.BeginTransaction();
             string action = eventType == (int)SwapEventTypeEnum.互换 ? ClientCashInCashOut.系统操作_互换 : ClientCashInCashOut.系统操作_平仓费;
-            try
+            ExecuteInTransaction(() =>
             {
-                new TradeUnwindService(this).CloseReCheck_SetTrade(unwindData.SwapTradeId, eventType == (int)SwapEventTypeEnum.互换, true);
+                CloseReCheckSetTrade(unwindData.SwapTradeId, eventType == (int)SwapEventTypeEnum.互换, true);
                 SaveSwapDeal(unwindData, eventType, 0, action, true);
-                DbContext.SaveChanges();
-                trans.Commit();
-            }
-            catch (Exception ex)
-            {
-                trans.Rollback();
-                throw;
-            }
-            finally
-            {
-                trans.Dispose();
-            }
+                SaveAllChanges();
+            });
         }
         /// <summary>
         /// 保存平仓/互换事件