ui(relTime): tick relative timestamps client-side so long-open tabs don't freeze

formatRelTime now wraps its label in <time data-rel-ts=...>, and
both layouts include a small ticker that re-renders every 30s.
Without this, a job-detail page rendered an hour ago kept showing
'2h ago' when the wall-clock truth was '3h ago'.

internal/server/ui/funcs.go

@@ -221,23 +221,40 @@ func formatBytes(n int64) template.HTML {
 // "in 5m"-style. Accepts *time.Time or time.Time so templates can
 // pass either without fighting Go's lack of an address-of operator.
 // Anything else returns "—".
-func formatRelTime(v any) string {
+//
+// The output is wrapped in a <time data-rel-ts="..."> element so a
+// small client-side ticker (see base.html) can refresh the label
+// without a full page reload — otherwise a long-open tab shows
+// timestamps frozen at render time.
+func formatRelTime(v any) template.HTML {
 	var t time.Time
 	switch x := v.(type) {
 	case time.Time:
 		t = x
 	case *time.Time:
 		if x == nil {
-			return "—"
+			return template.HTML("—")
 		}
 		t = *x
 	default:
-		return "—"
+		return template.HTML("—")
 	}
 	if t.IsZero() {
-		return "—"
+		return template.HTML("—")
 	}
-	d := time.Since(t)
+	label := relTimeLabel(time.Since(t))
+	return template.HTML(fmt.Sprintf(
+		`<time data-rel-ts="%s" title="%s">%s</time>`,
+		t.UTC().Format(time.RFC3339Nano),
+		t.UTC().Format("2006-01-02 15:04:05 UTC"),
+		label,
+	))
+}
+
+// relTimeLabel turns a duration-since-now into the short human label
+// used by formatRelTime (and mirrored verbatim by the JS ticker, so
+// keep the two in sync if you change the buckets).
+func relTimeLabel(d time.Duration) string {
 	suffix := "ago"
 	if d < 0 {
 		d = -d