The full switch: Monitors and Disks read only the sensor API; /api/metrics retired

- stock Monitors modules fed by one sensor stream, the catalog and one batch of
  histories (GET /api/sensors/history?ids=…), through sampleAdapter.ts
- the stream closes while the page is hidden and refills its curves on return
- Disks tab live rates from the stream
- new sensors: hamlab.sample_interval, ups.last_event
- stream: asking for about the sampling rate means every sample
- NUT runtime rounded at the source

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

web/src/Embed.tsx

@@ -18,7 +18,7 @@ export default function Embed() {
   const spec: WidgetSpec = { id: 'w', type, sensor, title: p.get('title') ?? undefined }
   const src: Source = { machine: p.get('machine') || null, token: p.get('token') ?? undefined }
   const every = Number(p.get('every')) || undefined
-  const live = useSensorStream<{ w: WidgetData }>(sensor ? { w: sensor } : null, src, every)
+  const live = useSensorStream<{ w: WidgetData }>(sensor ? { w: sensor } : null, { src, everyMs: every })
   return (
     <div className={'embed' + (p.get('bare') === '1' ? ' bare' : '')}>
       {!sensor ? <div className="error">embed needs ?sensor=</div> : (