更新主题样式，添加边框颜色变量；优化弹窗背景和标题样式；调整月度数据加载格式；改进图表初始化逻辑

Web/src/views/statisticsV2/Index.vue

@@ -314,7 +314,15 @@ const loadMonthlyData = async (year, month) => {
     // 加载每日统计
     const dailyResult = await getDailyStatistics({ year, month })
     if (dailyResult?.success && dailyResult.data) {
-      trendStats.value = dailyResult.data.filter(item => item != null)
+      // 转换数据格式：添加完整的 date 字段
+      trendStats.value = dailyResult.data
+        .filter(item => item != null)
+        .map(item => ({
+          date: `${year}-${month.toString().padStart(2, '0')}-${item.day.toString().padStart(2, '0')}`,
+          expense: item.expense || 0,
+          income: item.income || 0,
+          count: item.count || 0
+        }))
     }
   } catch (error) {
     console.error('加载月度数据失败:', error)