refactor(swap-eod): 抽出期末头寸纯函数并放宽可见性

SetFixedLegRealizedPnl 替换4处复制粘贴(清理L1296双分号); NormalizeInterestSignForReport 替换16行内联报表分支; CalculateWeightedMarginInterest private->public static。均为纯静态无实例依赖，配套无库单测锁定行为。

YLErpDAL/Modules/SwapModule/SwapEodPositionService.cs

@@ -1023,7 +1023,7 @@ namespace YLErp.Modules.SwapModule
             //累计已实现
             newEodPayPosition.RealizedInterest = eodPayPosition.RealizedInterest + newEodPayPosition.TdCloseInterest * ratio;
             newEodPayPosition.RealizedInterestFee = eodPayPosition.RealizedInterestFee + newEodPayPosition.TdCloseInterestFee;
-            newEodPayPosition.RealizedPnl = newEodPayPosition.RealizedInterest + newEodPayPosition.RealizedInterestFee;
+            SetFixedLegRealizedPnl(newEodPayPosition);
             var currencyRate = GetCurrencyRate(td.QuoteCurrency, td.SettlementCurrency, valueDate, true,
                 position.InterestDirection == (int)SwapDirectionEnum.收取 ? CurrencyRateType.Buy : CurrencyRateType.Sell);
             newEodPayPosition.TdCurrency = Convert.ToDecimal(currencyRate);
@@ -1157,7 +1157,7 @@ namespace YLErp.Modules.SwapModule
             //累计已实现
             newEodPayPosition.RealizedInterest = eodPayPosition.RealizedInterest + newEodPayPosition.TdCloseInterest * ratio;
             newEodPayPosition.RealizedInterestFee = eodPayPosition.RealizedInterestFee + newEodPayPosition.TdCloseInterestFee;
-            newEodPayPosition.RealizedPnl = newEodPayPosition.RealizedInterest + newEodPayPosition.RealizedInterestFee;
+            SetFixedLegRealizedPnl(newEodPayPosition);
             var currencyRate = GetCurrencyRate(td.QuoteCurrency, td.SettlementCurrency, valueDate, true,
                 position.InterestDirection == (int)SwapDirectionEnum.收取 ? CurrencyRateType.Buy : CurrencyRateType.Sell);
             newEodPayPosition.TdCurrency = Convert.ToDecimal(currencyRate);
@@ -1293,7 +1293,7 @@ namespace YLErp.Modules.SwapModule
             //累计已实现
             newEodPayPosition.RealizedInterest = eodPayPosition.RealizedInterest + newEodPayPosition.TdCloseInterest * ratio;
             newEodPayPosition.RealizedInterestFee = eodPayPosition.RealizedInterestFee + newEodPayPosition.TdCloseInterestFee;
-            newEodPayPosition.RealizedPnl = newEodPayPosition.RealizedInterest + newEodPayPosition.RealizedInterestFee; ;
+            SetFixedLegRealizedPnl(newEodPayPosition);
             var currencyRate = GetCurrencyRate(td.QuoteCurrency, td.SettlementCurrency, valueDate, true,
                 position.InterestDirection == (int)SwapDirectionEnum.收取 ? CurrencyRateType.Buy : CurrencyRateType.Sell);
             newEodPayPosition.TdCurrency = Convert.ToDecimal(currencyRate);
@@ -1415,7 +1415,7 @@ namespace YLErp.Modules.SwapModule
             //累计已实现
             newEodPayPosition.RealizedInterest = eodPayPosition.RealizedInterest + newEodPayPosition.TdCloseInterest * ratio;
             newEodPayPosition.RealizedInterestFee = eodPayPosition.RealizedInterestFee + newEodPayPosition.TdCloseInterestFee;
-            newEodPayPosition.RealizedPnl = newEodPayPosition.RealizedInterest + newEodPayPosition.RealizedInterestFee;
+            SetFixedLegRealizedPnl(newEodPayPosition);
             var currencyRate = GetCurrencyRate(td.QuoteCurrency, td.SettlementCurrency, valueDate, true,
                 eodPayPosition.InterestDirection == (int)SwapDirectionEnum.收取 ? CurrencyRateType.Buy : CurrencyRateType.Sell);
             newEodPayPosition.TdCurrency = Convert.ToDecimal(currencyRate);
@@ -2087,6 +2087,28 @@ namespace YLErp.Modules.SwapModule
                    + position.RealizedInterestFee;
         }
 
+        /// <summary>
+        /// 风险报表符号归一化：把历史两种符号口径的 TdCloseInterest/RealizedInterest
+        /// 统一按"绝对金额 × 业务方向"重写。普通利息腿收取为正、支付为负；
+        /// 预付金腿利息方向与保证金本金方向相反。随后重算 RealizedPnl。
+        /// 抽为 public static 纯函数以支持无库单测（见 SwapReportInterestSignNormalizeTest）。
+        /// 仅当 InterestDirection > 0 时执行（与原内联逻辑等价）。
+        /// </summary>
+        public static void NormalizeInterestSignForReport(eod_swap_position position)
+        {
+            if (position.InterestDirection <= 0) return;
+
+            var interestRatio = position.InterestDirection == (int)SwapDirectionEnum.收取 ? 1m : -1m;
+            if (ConsTrade.InterestMarginModels.Contains(position.InterestMode))
+            {
+                interestRatio = -interestRatio;
+            }
+            position.TdCloseInterest = Math.Abs(position.TdCloseInterest) * interestRatio;
+            position.RealizedInterest = Math.Abs(position.RealizedInterest) * interestRatio;
+            // 兼容修复前已落库的利息腿：当时只累计了明细字段，未同步写入 RealizedPnl。
+            position.RealizedPnl = position.RealizedInterest + position.RealizedInterestFee;
+        }
+
         /// <summary>
         /// 获取多空组合 平仓详细
         /// </summary>
@@ -2179,22 +2201,9 @@ namespace YLErp.Modules.SwapModule
                 item.eodPosition.PosiNetFeePrice *= multiplier;
                 item.eodPosition.PosiNetNoFeePrice *= multiplier;
                 item.eodPosition.UnderlyingPrice *= multiplier;
-                if (item.eodPosition.InterestDirection > 0)
-                {
-                    // 历史数据的 TdCloseInterest、RealizedInterest 存在两种符号口径，
-                    // 风险报表统一按绝对金额和业务方向还原：普通利息腿收取为正、支付为负，
-                    // 预付金腿的利息方向与保证金本金方向相反。
-                    var interestRatio = item.eodPosition.InterestDirection == (int)SwapDirectionEnum.收取 ? 1m : -1m;
-                    if (ConsTrade.InterestMarginModels.Contains(item.eodPosition.InterestMode))
-                    {
-                        interestRatio = -interestRatio;
-                    }
-                    item.eodPosition.TdCloseInterest = Math.Abs(item.eodPosition.TdCloseInterest) * interestRatio;
-                    item.eodPosition.RealizedInterest = Math.Abs(item.eodPosition.RealizedInterest) * interestRatio;
-                    // 兼容修复前已落库的利息腿：当时只累计了明细字段，未同步写入 RealizedPnl。
-                    item.eodPosition.RealizedPnl = item.eodPosition.RealizedInterest
-                                                    + item.eodPosition.RealizedInterestFee;
-                }
+                // 历史数据的 TdCloseInterest、RealizedInterest 存在两种符号口径，
+                // 风险报表统一按绝对金额和业务方向还原，并重算 RealizedPnl。
+                NormalizeInterestSignForReport(item.eodPosition);
             }
             return retListResult;
 
@@ -2630,12 +2639,24 @@ namespace YLErp.Modules.SwapModule
         /// <summary>
         /// 计算预付金利息金额。InterestIncomeSum 已是各腿利息金额，
         /// 按收取为正、支付为负直接轧差求和，不做本金加权。
+        /// 抽为 public static 纯函数以支持无库单测（见 SwapWeightedMarginInterestTest）。
         /// </summary>
-        private static decimal CalculateWeightedMarginInterest(IEnumerable<eod_swap_position> margins)
+        public static decimal CalculateWeightedMarginInterest(IEnumerable<eod_swap_position> margins)
         {
             return margins.Sum(x =>
                 x.InterestIncomeSum * (x.InterestDirection == (int)SwapDirectionEnum.收取 ? 1 : -1));
         }
+
+        /// <summary>
+        /// 固定利息腿的累计已实现盈亏 = 累计已实现利息 + 累计已实现利息费用。
+        /// 4 处 SaveAutoEodInterestPosition/SaveEodInterestPosition 路径口径一致，
+        /// 抽为 public static 纯函数以支持无库单测（见 SwapFixedLegRealizedPnlTest），
+        /// 并消除复制粘贴带来的笔误风险（如 L1296 历史双分号）。
+        /// </summary>
+        public static void SetFixedLegRealizedPnl(eod_swap_position position)
+        {
+            position.RealizedPnl = position.RealizedInterest + position.RealizedInterestFee;
+        }
         /// <summary>
         /// 将数据库中以公司/交易簿记方向保存的日终字段转换为客户视角。
         /// 该转换必须在拆分浮动收益、费用和期间付息/分红之前完成，