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

frontend/lib/services/openflare/dashboard.service.ts

@@ -89,6 +89,9 @@ function normalizeTrafficTrendPoints(
           request_count: Number(item[1] ?? 0),
           error_count: Number(item[2] ?? 0),
           unique_visitor_count: Number(item[3] ?? 0),
+          status_2xx_count: Number(item[4] ?? 0),
+          status_4xx_count: Number(item[5] ?? 0),
+          status_5xx_count: Number(item[6] ?? 0),
         }
       : item,
   );

frontend/lib/services/openflare/types.ts

@@ -1159,6 +1159,9 @@ export interface TrafficTrendPoint {
   request_count: number;
   error_count: number;
   unique_visitor_count: number;
+  status_2xx_count: number;
+  status_4xx_count: number;
+  status_5xx_count: number;
 }
 
 export interface CapacityTrendPoint {
@@ -1227,7 +1230,15 @@ export interface DashboardOverview {
   nodes: DashboardNodeHealth[];
 }
 
-export type CompactTrafficTrendPoint = [string, number, number, number];
+export type CompactTrafficTrendPoint = [
+  string,
+  number,
+  number,
+  number,
+  number,
+  number,
+  number,
+];
 export type CompactCapacityTrendPoint = [string, number, number, number];
 /** [bucket, bytes_received, bytes_provided, reported_nodes] */
 export type CompactNetworkTrendPoint = [string, number, number, number];