feat(health): 增加历史状态条指标 Tooltip

- 为健康监控时间轴返回 timeline_details 分段指标
- Hover 历史状态柱时展示总请求/成功/失败/可用率/状态
- 展示平均耗时/TTFB/速度和完整时间范围
- 修复历史状态柱 Tooltip 触发区域不可用的问题
- 补齐前端类型、详情抽屉透传和 mock 数据

frontend/src/features/providers/components/HealthMonitorDetailDrawer.vue

@@ -177,6 +177,7 @@ const sourceMonitor = computed<HealthRelatedMonitor | null>(() => {
     avg_first_byte_ms: source.avgFirstByteMs,
     avg_tps: source.avgTps,
     timeline: source.timeline || undefined,
+    timeline_details: source.timelineDetails || undefined,
     time_range_start: source.timeRangeStart || null,
     time_range_end: source.timeRangeEnd || null
   }
@@ -281,6 +282,7 @@ function buildSourceFromRelatedMonitor(monitor: HealthRelatedMonitor): HealthMon
     avgFirstByteMs: monitor.avg_first_byte_ms,
     avgTps: monitor.avg_tps,
     timeline: monitor.timeline || null,
+    timelineDetails: monitor.timeline_details || null,
     timeRangeStart: monitor.time_range_start || null,
     timeRangeEnd: monitor.time_range_end || null
   }