feat(dashboard): 首页请求趋势拆分状态码并合并容量到业务流量

- 24 小时请求趋势拆分展示请求总量与 200/400/500 状态码请求量，独占一行；
  时间桶聚合新增 status_200/400/500_count（CH countIf、PG FILTER），
  请求趋势改为基于原始桶聚合（小时 rollup 无状态码口径）
- 首页移除宿主机磁盘指标，容量趋势（CPU/内存）并入业务流量卡片展示
- 压缩协议 traffic_24h 扩展为 7 元组，前端归一化同步更新

internal/apps/openflare/dashboard/logics.go

@@ -330,11 +330,15 @@ func compressDistributionItems(items []observability.DistributionItem) [][]any {
 func compressTrafficTrendPoints(points []observability.TrafficTrendPoint) [][]any {
 	rows := make([][]any, 0, len(points))
 	for _, point := range points {
+		// Compact layout: [0] bucket, [1] request, [2] error, [3] uv, [4] 2xx, [5] 4xx, [6] 5xx
 		rows = append(rows, []any{
 			point.BucketStartedAt,
 			point.RequestCount,
 			point.ErrorCount,
 			point.UniqueVisitorCount,
+			point.Status2xxCount,
+			point.Status4xxCount,
+			point.Status5xxCount,
 		})
 	}
 	return rows

internal/apps/openflare/dashboard/logics_test.go

@@ -143,7 +143,7 @@ func TestGetOverviewStructure(t *testing.T) {
 	require.Len(t, overview.Trends.Network24h, 24)
 	require.Len(t, overview.Trends.DiskIO24h, 24)
 	for _, row := range overview.Trends.Traffic24h {
-		require.Len(t, row, 4)
+		require.Len(t, row, 7)
 	}
 	for _, row := range overview.Trends.Capacity24h {
 		require.Len(t, row, 4)