feat(日历): 添加交易热力图组件展示每日交易统计

- 新增 ContributionHeatmap 组件实现类似 GitHub 贡献热力图的可视化
- 添加 getDailyStatisticsRange API 接口获取日期范围内的每日统计数据
- 调整日历页面布局以容纳热力图组件
- 热力图支持动态阈值计算和暗黑模式适配
- 交易变更时自动刷新热力图数据

WebApi/Controllers/TransactionRecordController.cs

@@ -284,6 +284,33 @@ public class TransactionRecordController(
         }
     }
 
+    /// <summary>
+    /// 获取指定日期范围内的每日统计
+    /// </summary>
+    [HttpGet]
+    public async Task<BaseResponse<List<DailyStatisticsDto>>> GetDailyStatisticsRangeAsync(
+        [FromQuery] DateTime startDate,
+        [FromQuery] DateTime endDate
+    )
+    {
+        try
+        {
+            // 确保包含结束日期当天
+            var effectiveEndDate = endDate.Date.AddDays(1);
+            var effectiveStartDate = startDate.Date;
+
+            var statistics = await transactionRepository.GetDailyStatisticsByRangeAsync(effectiveStartDate, effectiveEndDate);
+            var result = statistics.Select(s => new DailyStatisticsDto(s.Key, s.Value.count, s.Value.amount)).ToList();
+
+            return result.Ok();
+        }
+        catch (Exception ex)
+        {
+            logger.LogError(ex, "获取日历统计数据失败，开始: {StartDate}, 结束: {EndDate}", startDate, endDate);
+            return $"获取日历统计数据失败: {ex.Message}".Fail<List<DailyStatisticsDto>>();
+        }
+    }
+
     /// <summary>
     /// 获取月度统计数据
     /// </summary>