feat(预算): 添加预算趋势分析功能并优化图表展示

重构预算分析图表组件，添加每日/每月趋势统计功能：
1. 在Repository层添加趋势统计接口
2. 在Service层实现趋势数据计算逻辑
3. 优化前端图表展示，合并偏差分析图表
4. 改进燃尽图使用实际趋势数据
5. 调整UI样式和交互体验

Service/BudgetService.cs

@@ -230,6 +230,91 @@ public class BudgetService(
         result.Current = totalCurrent;
         result.Rate = totalLimit > 0 ? totalCurrent / totalLimit * 100 : 0;
 
+        // 计算每日/每月趋势
+        var transactionType = category switch
+        {
+            BudgetCategory.Expense => TransactionType.Expense,
+            BudgetCategory.Income => TransactionType.Income,
+            _ => TransactionType.None
+        };
+
+        if (transactionType != TransactionType.None)
+        {
+            var hasGlobalBudget = relevant.Any(b => b.SelectedCategories == null || b.SelectedCategories.Length == 0);
+
+            var allClassifies = hasGlobalBudget
+                ? new List<string>()
+                : relevant
+                    .SelectMany(b => b.SelectedCategories)
+                    .Distinct()
+                    .ToList();
+
+            DateTime startDate, endDate;
+            bool groupByMonth = false;
+
+            if (statType == BudgetPeriodType.Month)
+            {
+                startDate = new DateTime(referenceDate.Year, referenceDate.Month, 1);
+                endDate = startDate.AddMonths(1).AddDays(-1);
+                groupByMonth = false;
+            }
+            else // Year
+            {
+                startDate = new DateTime(referenceDate.Year, 1, 1);
+                endDate = startDate.AddYears(1).AddDays(-1);
+                groupByMonth = true;
+            }
+
+            var dailyStats = await transactionRecordRepository.GetFilteredTrendStatisticsAsync(
+                startDate,
+                endDate,
+                transactionType,
+                allClassifies,
+                groupByMonth);
+
+            decimal accumulated = 0;
+            var now = DateTime.Now;
+
+            if (statType == BudgetPeriodType.Month)
+            {
+                var daysInMonth = DateTime.DaysInMonth(startDate.Year, startDate.Month);
+                for (int i = 1; i <= daysInMonth; i++)
+                {
+                    var currentDate = new DateTime(startDate.Year, startDate.Month, i);
+                    if (currentDate.Date > now.Date)
+                    {
+                        result.Trend.Add(null);
+                        continue;
+                    }
+
+                    if (dailyStats.TryGetValue(currentDate.Date, out var amount))
+                    {
+                        accumulated += amount;
+                    }
+                    result.Trend.Add(accumulated);
+                }
+            }
+            else // Year
+            {
+                for (int i = 1; i <= 12; i++)
+                {
+                    var currentMonthDate = new DateTime(startDate.Year, i, 1);
+                    
+                    if (currentMonthDate.Year > now.Year || (currentMonthDate.Year == now.Year && i > now.Month))
+                    {
+                        result.Trend.Add(null);
+                        continue;
+                    }
+
+                    if (dailyStats.TryGetValue(currentMonthDate, out var amount))
+                    {
+                        accumulated += amount;
+                    }
+                    result.Trend.Add(accumulated);
+                }
+            }
+        }
+
         return result;
     }
 
@@ -896,6 +981,11 @@ public class BudgetStatsDto
     /// 预算项数量
     /// </summary>
     public int Count { get; set; }
+
+    /// <summary>
+    /// 每日/每月累计金额趋势（对应当前周期内的实际发生额累计值）
+    /// </summary>
+    public List<decimal?> Trend { get; set; } = new();
 }
 
 /// <summary>