fix(swap): 修复续做交易中持仓和名义本金的初始化问题

- 恢复初始持仓名义本金，使用OriginalStockEqvNotional和OriginalNotional的原始值
- 只克隆初始持仓(IsInitial=true)，避免带入部分平仓后的实时持仓
- 设置预付金腿HappenDate为新交易起始日，非预付金腿置为null
- 清空源交易的事件/持仓快照等集合，避免与源交易共享引用
- 初始化swap_Events、swap_Flow_Events等集合为空列表

YLErpWeb/Controllers/SwapTrade2Controller.cs

@@ -139,6 +139,14 @@ namespace YLErp.Web.Controllers
             renewTrade.ValidState = null;
             renewTrade.CreateDate = null;
             renewTrade.TradeSource = null;
+            // 恢复初始持仓名义本金（源交易若有过部分平仓，StockEqvNotional/TradeAmount 已递减，
+            // 但 OriginalStockEqvNotional 和 OriginalNotional 始终保留原始值不被递减）
+            if (renewTrade.OriginalStockEqvNotional != null)
+            {
+                renewTrade.StockEqvNotional = (double)renewTrade.OriginalStockEqvNotional;
+            }
+
+            renewTrade.TradeAmount = renewTrade.OriginalNotional ?? renewTrade.TradeAmount;
             renewTrade.trade_extend = sourceTrade.trade_extend?.Clone() ?? defaultTrade.trade_extend;
             renewTrade.trade_extend.TradeId = 0;
             renewTrade.trade_Initial_Margin = sourceTrade.trade_Initial_Margin?.Clone() ?? new trade_initial_margin();
@@ -146,7 +154,10 @@ namespace YLErp.Web.Controllers
             renewTrade.MetaDic = sourceTrade.MetaDic == null
                 ? new Dictionary<string, string>()
                 : new Dictionary<string, string>(sourceTrade.MetaDic);
-            renewTrade.swap_positions = sourceTrade.swap_positions.Select(position =>
+            // 只克隆初始持仓（IsInitial=true），避免将部分平仓后的实时持仓（名义本金已递减）带入续做交易
+            renewTrade.swap_positions = sourceTrade.swap_positions
+                ?.Where(p => p.IsInitial)
+                .Select(position =>
             {
                 var renewPosition = position.Clone();
                 renewPosition.id = 0;
@@ -155,11 +166,23 @@ namespace YLErp.Web.Controllers
                 renewPosition.PosiNumber = null;
                 renewPosition.PosiStartDate = defaultTrade.StartDate.Value;
                 renewPosition.PosiMatuirityDate = null;
-                renewPosition.HappenDate = null;
+                // 预付金腿的 HappenDate 用于后续生成资金流水（ResetMarginAmount 按 HappenDate 过滤），
+                // 续做时设为新交易的起始日；非预付金腿的 HappenDate 无实际用途，置 null
+                renewPosition.HappenDate =
+                    position.InterestMode == (int)YLErp.DBModels.InterestModeEnum.初始预付金
+                        ? defaultTrade.StartDate
+                        : null;
                 renewPosition.InterestSwapInterval = null;
                 renewPosition.Obervation = null;
                 return renewPosition;
-            }).ToList();
+            }).ToList() ?? new List<swap_position>();
+            // 清空源交易的事件/持仓快照等集合，避免与源交易共享引用
+            renewTrade.swap_Events = new List<swap_event>();
+            renewTrade.swap_Flow_Events = new List<swap_flow_event>();
+            renewTrade.eod_swaps = new List<eod_swap>();
+            renewTrade.inital_eod_swap_positions = new List<eod_swap_position>();
+            renewTrade.eod_swap_positions = new List<eod_swap_position>();
+            renewTrade.ClientCashInCashOutList = new List<ClientCashInCashOut>();
             return renewTrade;
         }
         /// <summary>