feat: 交易后自动触发净值历史重算

- CreateTransaction完成后删除该交易日期之后的净值记录
- 下次请求收益曲线时自动重新计算
- 修改CreateTransaction为async方法
- 注入IPortfolioNavService到PortfolioService

流程：
1. 用户买入/卖出 → 创建交易记录
2. 删除交易日期之后的净值历史
3. 下次请求收益曲线 → 自动回填缺失数据

AssetManager.API/Controllers/PortfolioController.cs

@@ -263,7 +263,7 @@ public class PortfolioController : ControllerBase
     /// <param name="request">交易请求参数（类型、标的、数量、价格等）</param>
     /// <returns>创建的交易记录</returns>
     [HttpPost("transactions")]
-    public ActionResult<ApiResponse<CreateTransactionResponse>> CreateTransaction([FromBody] CreateTransactionRequest request)
+    public async Task<ActionResult<ApiResponse<CreateTransactionResponse>>> CreateTransaction([FromBody] CreateTransactionRequest request)
     {
         var userId = GetCurrentUserId();
         if (string.IsNullOrEmpty(userId))
@@ -325,7 +325,7 @@ public class PortfolioController : ControllerBase
             }
         }
         
-        var response = _portfolioService.CreateTransaction(request, userId);
+        var response = await _portfolioService.CreateTransaction(request, userId);
 
         _logger.LogInformation("Transaction created successfully");
         

AssetManager.Services/IPortfolioService.cs

@@ -10,5 +10,5 @@ public interface IPortfolioService
     PortfolioDetailResponse GetPortfolioById(string id, string userId);
     Task<PortfolioDetailResponse> GetPortfolioByIdAsync(string id, string userId);
     GetTransactionsResponse GetTransactions(string portfolioId, string userId, int limit, int offset);
-    CreateTransactionResponse CreateTransaction(CreateTransactionRequest request, string userId);
+    Task<CreateTransactionResponse> CreateTransaction(CreateTransactionRequest request, string userId);
 }

AssetManager.Services/PortfolioService.cs

@@ -11,17 +11,20 @@ public class PortfolioService : IPortfolioService
     private readonly ISqlSugarClient _db;
     private readonly IMarketDataService _marketDataService;
     private readonly IExchangeRateService _exchangeRateService;
+    private readonly IPortfolioNavService _navService;
     private readonly ILogger<PortfolioService> _logger;
 
     public PortfolioService(
         ISqlSugarClient db, 
         IMarketDataService marketDataService, 
         IExchangeRateService exchangeRateService,
+        IPortfolioNavService navService,
         ILogger<PortfolioService> logger)
     {
         _db = db;
         _marketDataService = marketDataService;
         _exchangeRateService = exchangeRateService;
+        _navService = navService;
         _logger = logger;
     }
 
@@ -444,7 +447,7 @@ public class PortfolioService : IPortfolioService
         };
     }
 
-    public CreateTransactionResponse CreateTransaction(CreateTransactionRequest request, string userId)
+    public async Task<CreateTransactionResponse> CreateTransaction(CreateTransactionRequest request, string userId)
     {
         // 验证投资组合是否属于该用户
         var portfolio = _db.Queryable<Portfolio>()
@@ -602,6 +605,21 @@ public class PortfolioService : IPortfolioService
         portfolio.UpdatedAt = DateTime.Now;
         _db.Updateable(portfolio).ExecuteCommand();
 
+        // 删除该交易日期之后的净值历史记录，下次请求收益曲线时会自动重新计算
+        try
+        {
+            var deletedCount = await _navService.DeleteNavHistoryAfterDateAsync(request.portfolioId, transactionTime.Date);
+            if (deletedCount > 0)
+            {
+                _logger.LogInformation("交易创建后删除净值历史: PortfolioId={PortfolioId}, Date={Date}, Count={Count}",
+                    request.portfolioId, transactionTime.Date, deletedCount);
+            }
+        }
+        catch (Exception ex)
+        {
+            _logger.LogWarning(ex, "删除净值历史失败，将在下次请求时重新计算");
+        }
+
         return new CreateTransactionResponse
         {
             id = transaction.Id,