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>

internal/metrics/metrics.go

@@ -136,16 +136,6 @@ type Sample struct {
 	fsT, upsT int64 // when the slow sections were really read; sensors report these, not T
 }
 
-// Series is the compact history the UI seeds its sparklines from.
-type Series struct {
-	T    []int64                         `json:"t"`
-	CPU  []float64                       `json:"cpu"`
-	Mem  []uint64                        `json:"mem"`
-	Net  map[string]map[string][]float64 `json:"net"`  // iface -> {rx,tx}
-	Disk map[string]map[string][]float64 `json:"disk"` // name -> {r,w,u}
-	Temp map[string][]float64            `json:"temp"` // "chip/label" -> °C
-}
-
 type Collector struct {
 	mu       sync.RWMutex
 	ring     []Sample
@@ -236,44 +226,6 @@ func (c *Collector) Latest() (Sample, bool) {
 	return c.ring[len(c.ring)-1], true
 }
 
-func (c *Collector) History() Series {
-	c.mu.RLock()
-	defer c.mu.RUnlock()
-	n := len(c.ring)
-	s := Series{T: make([]int64, n), CPU: make([]float64, n), Mem: make([]uint64, n),
-		Net: map[string]map[string][]float64{}, Disk: map[string]map[string][]float64{}, Temp: map[string][]float64{}}
-	series := func(m map[string]map[string][]float64, key string, keys ...string) map[string][]float64 {
-		v, ok := m[key]
-		if !ok {
-			v = map[string][]float64{}
-			for _, k := range keys {
-				v[k] = make([]float64, n)
-			}
-			m[key] = v
-		}
-		return v
-	}
-	for i, smp := range c.ring {
-		s.T[i], s.CPU[i], s.Mem[i] = smp.T, smp.CPU, smp.Mem.Used
-		for _, x := range smp.Net {
-			v := series(s.Net, x.Iface, "rx", "tx")
-			v["rx"][i], v["tx"][i] = x.RxBps, x.TxBps
-		}
-		for _, d := range smp.Disks {
-			v := series(s.Disk, d.Name, "r", "w", "u")
-			v["r"][i], v["w"][i], v["u"][i] = d.ReadBps, d.WriteBps, d.UtilPct
-		}
-		for _, t := range smp.Temps {
-			k := t.Chip + "/" + t.Label
-			if s.Temp[k] == nil {
-				s.Temp[k] = make([]float64, n)
-			}
-			s.Temp[k][i] = t.C
-		}
-	}
-	return s
-}
-
 // ---- sampling ----
 
 func (c *Collector) sample() {
@@ -853,7 +805,7 @@ func upsNUT() *UPS {
 	u.InV = leadingNum(kv["input.voltage"])
 	u.OutV = leadingNum(kv["output.voltage"])
 	u.BatteryPct = leadingNum(kv["battery.charge"])
-	u.RuntimeMin = leadingNum(kv["battery.runtime"]) / 60
+	u.RuntimeMin = round1(leadingNum(kv["battery.runtime"]) / 60)
 	u.LoadPct = leadingNum(kv["ups.load"])
 	u.LoadW = leadingNum(kv["ups.realpower"])
 	if u.LoadW == 0 {