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>

SENSORS.md

@@ -50,6 +50,7 @@ On a hub, every one is also at `/api/nodes/<machine>/sensors…` for each manage
 | `GET /api/sensors` | Catalog, with current values. `?ids=fan.*,cpu.usage` narrows it. |
 | `GET /api/sensors/{id}` | One sensor. `?format=text` → the bare value as text/plain. |
 | `GET /api/sensors/{id}/history` | `{id, unit, t[], v[]}` — what the ring holds (300 samples at the sampling interval). Numbers only. |
+| `GET /api/sensors/history?ids=cpu.usage,net.*.rx` | Many histories in one request: `{series: [{id, unit, t[], v[]}]}`. A sensor younger than the ring has a shorter series. |
 | `POST /api/sensors/query` | Shaped query, below. |
 | `GET /api/sensors/query?k=selector&…` | The same, flat, for consumers that can only fetch a URL. |
 
@@ -172,7 +173,14 @@ facts, never live. An `iframe` of the embed is live.
 
 ## Not yet
 
-- The stock Monitors modules (CPU, Temperatures, Network…) still read `/api/metrics`;
-  only custom widgets run on sensors. Porting them is the remaining dogfooding.
 - Per-unit service sensors, containers, token restriction to ID patterns, a fleet-wide
   query in one request.
+
+## What Ham Lab itself runs on
+
+Since 2026-09-19 the Monitors tab (stock modules and custom widgets) and the Disks tab's
+live rates read only this API: the catalog once, one batch of histories, one stream —
+closed while the page is hidden, refilled when it returns. `web/src/sampleAdapter.ts` is
+the seam that hands the stock modules the object they were written against. The old
+`/api/metrics` and `/api/metrics/history` are gone. `hamlab.sample_interval` is the
+sampler's own rate, as a sensor.