feat: 自动触发净值计算

1. 创建组合后，如有持仓则自动计算净值
2. 创建交易后，自动更新当日净值
3. 异步执行，不阻塞主流程

AssetManager.Services/PortfolioFacade.cs

@@ -81,7 +81,22 @@ public class PortfolioFacade : IPortfolioFacade
             throw new UnauthorizedAccessException("组合不存在或无权访问");
         }
         
-        return await _portfolioService.CreateTransactionAsync(portfolioId, request, userId);
+        var transaction = await _portfolioService.CreateTransactionAsync(portfolioId, request, userId);
+        
+        // 交易完成后，异步触发净值更新
+        _ = Task.Run(async () =>
+        {
+            try
+            {
+                await _navService.CalculateAndSaveDailyNavAsync(portfolioId);
+            }
+            catch (Exception ex)
+            {
+                _logger.LogWarning(ex, "交易后净值更新失败: {PortfolioId}", portfolioId);
+            }
+        });
+        
+        return transaction;
     }
 
     public async Task<List<TransactionItem>> GetTransactionsAsync(string portfolioId, GetTransactionsRequest request, string userId)
@@ -167,7 +182,26 @@ public class PortfolioFacade : IPortfolioFacade
             }
         }
         
-        return await _portfolioService.CreatePortfolioAsync(request, userId);
+        var response = await _portfolioService.CreatePortfolioAsync(request, userId);
+        
+        // 如果创建了持仓，自动触发净值计算
+        if (request.Stocks != null && request.Stocks.Any())
+        {
+            _logger.LogInformation("新组合包含持仓，触发净值计算: {PortfolioId}", response.Id);
+            _ = Task.Run(async () =>
+            {
+                try
+                {
+                    await _navService.CalculateAndSaveDailyNavAsync(response.Id);
+                }
+                catch (Exception ex)
+                {
+                    _logger.LogWarning(ex, "新组合净值计算失败: {PortfolioId}", response.Id);
+                }
+            });
+        }
+        
+        return response;
     }
 
     /// <summary>