fix: 添加 /api/v1/portfolio/transactions 路由支持 query parameter

前端请求格式: /api/v1/portfolio/transactions?portfolioId=xxx
后端原有路由: /api/v1/portfolio/{id}/transactions

添加 [HttpGet("transactions")] 支持 query parameter 方式

AssetManager.API/Controllers/PortfolioController.cs

@@ -98,6 +98,50 @@ public class PortfolioController : ControllerBase
         });
     }
 
+    /// <summary>
+    /// 获取交易记录（通过 query parameter）
+    /// </summary>
+    [HttpGet("transactions")]
+    public async Task<ActionResult<ApiResponse<GetTransactionsResponse>>> GetTransactionsByQuery(
+        [FromQuery] string portfolioId,
+        [FromQuery] int limit = 20,
+        [FromQuery] int offset = 0)
+    {
+        var userId = GetCurrentUserId();
+        
+        try
+        {
+            var request = new GetTransactionsRequest
+            {
+                PortfolioId = portfolioId,
+                Limit = limit,
+                Offset = offset
+            };
+            
+            var transactions = await _portfolioFacade.GetTransactionsAsync(portfolioId, request, userId);
+            
+            return Ok(new ApiResponse<GetTransactionsResponse>
+            {
+                code = Models.StatusCodes.Success,
+                data = new GetTransactionsResponse
+                {
+                    Items = transactions,
+                    Total = transactions.Count
+                },
+                message = "success"
+            });
+        }
+        catch (UnauthorizedAccessException)
+        {
+            return NotFound(new ApiResponse<GetTransactionsResponse>
+            {
+                code = Models.StatusCodes.NotFound,
+                data = null,
+                message = "组合不存在"
+            });
+        }
+    }
+
     /// <summary>
     /// 获取投资组合详情
     /// </summary>