feat(channel-monitor): redesign user dashboard as card grid

Reference check-cx UI: INTELLIGENCE MONITOR hero + 3-column card grid
with 60-point timeline bars.

Backend:
- Add PrimaryPingLatencyMs + Timeline[60] to UserMonitorView
- ListRecentHistoryForMonitors: batch CTE + ROW_NUMBER() window query
- indexLatestByModel / indexAvailabilityByModel helpers

Frontend:
- 7 new components: ProviderIcon, MonitorMetricPair, MonitorAvailabilityRow,
  MonitorTimeline, MonitorHero, MonitorCard, MonitorCardGrid
- ChannelStatusView 381→~180 lines (delegated to subcomponents)
- AbortController reload concurrency protection
- HSL 0-120° availability color mapping
- Replace emoji with Icon component (bolt / globe)
- i18n: monitorCommon.* shared namespace, channelStatus.hero.*

Bump VERSION to 0.1.114.24

backend/internal/service/channel_monitor_const.go

@@ -65,6 +65,9 @@ const (
 	// MonitorHistoryMaxLimit 历史查询最大返回条数（handler 层共享）。
 	MonitorHistoryMaxLimit = 1000
 
+	// monitorTimelineMaxPoints 用户视图 timeline 每个监控最多返回的历史点数。
+	monitorTimelineMaxPoints = 60
+
 	// monitorEndpointResolveTimeout validateEndpoint 解析 hostname 的最长耗时。
 	monitorEndpointResolveTimeout = 5 * time.Second