Status: latency the panel can actually show

PocketBase and the Web App share a Docker network and answer a health
probe in well under a millisecond. Milliseconds() truncated that to 0,
and omitempty on an int64 dropped the zero from the JSON, so the panel
saw no latencyMs at all and rendered an em dash.

Latency is now a *float64 rounded to one decimal, computed from
Microseconds(). The pointer keeps an absent measurement — the API
Server row, which probes nothing — distinct from a genuinely fast one.
pbProbe follows suit, since it copies straight off svcHealth.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

API Server/internal/api/settings.go

@@ -18,7 +18,7 @@ import (
 type pbProbe struct {
 	Reachable  bool     `json:"reachable"`
 	HTTPStatus int      `json:"httpStatus,omitempty"`
-	LatencyMs  int64  `json:"latencyMs,omitempty"`
+	LatencyMs  *float64 `json:"latencyMs,omitempty"`
 	Superuser  bool     `json:"superuser"`
 	Detail     string   `json:"detail,omitempty"`
 }

API Server/internal/api/status.go

@@ -3,6 +3,7 @@ package api
 import (
 	"context"
 	"io"
+	"math"
 	"net/http"
 	"sync"
 	"time"
@@ -11,12 +12,21 @@ import (
 // svcHealth is the health of one upstream service, as shown on the panel.
 type svcHealth struct {
 	Status     string `json:"status"` // "ok" | "down"
-	LatencyMs  int64  `json:"latencyMs,omitempty"`
 	HTTPStatus int    `json:"httpStatus,omitempty"`
 	URL        string `json:"url,omitempty"`
+	// Fractional, and a pointer so an absent measurement (this process) stays
+	// distinguishable from a genuinely fast one: neighbours sharing a Docker
+	// network answer in well under a millisecond.
+	LatencyMs *float64 `json:"latencyMs,omitempty"`
 	Error     string   `json:"error,omitempty"`
 }
 
+// latencyMs is elapsed time in milliseconds, kept to one decimal.
+func latencyMs(d time.Duration) *float64 {
+	ms := math.Round(float64(d.Microseconds())/100) / 10
+	return &ms
+}
+
 // healthClient is a short-timeout client for probing upstreams so a hung
 // dependency can't stall the status endpoint.
 var healthClient = &http.Client{Timeout: 4 * time.Second}
@@ -29,7 +39,7 @@ func probe(ctx context.Context, url string) svcHealth {
 		return svcHealth{Status: "down", URL: url, Error: err.Error()}
 	}
 	resp, err := healthClient.Do(req)
-	lat := time.Since(start).Milliseconds()
+	lat := latencyMs(time.Since(start))
 	if err != nil {
 		return svcHealth{Status: "down", URL: url, LatencyMs: lat, Error: err.Error()}
 	}