feat: 优化预算管理界面，增强预算编辑功能，添加预算删除接口

WebApi/Controllers/Dto/BudgetDto.cs

@@ -12,6 +12,8 @@ public class BudgetDto
     public bool IsStopped { get; set; }
     public string StartDate { get; set; } = string.Empty;
     public string Period { get; set; } = string.Empty;
+    public DateTime? PeriodStart { get; set; }
+    public DateTime? PeriodEnd { get; set; }
 
     public static BudgetDto FromEntity(BudgetRecord entity, decimal currentAmount = 0, DateTime? referenceDate = null)
     {
@@ -38,7 +40,9 @@ public class BudgetDto
                 BudgetPeriodType.Month => $"{start:yy}年第{start.Month}月",
                 BudgetPeriodType.Week => $"{start:yy}年第{System.Globalization.CultureInfo.CurrentCulture.Calendar.GetWeekOfYear(start, System.Globalization.CalendarWeekRule.FirstDay, DayOfWeek.Monday)}周",
                 _ => $"{start:yyyy-MM-dd} ~ {end:yyyy-MM-dd}"
-            }
+            },
+            PeriodStart = start,
+            PeriodEnd = end
         };
     }
 }