web: a failure names itself on the page (issue #167)

The Series list row's fact line gains the failure word and its age in one
mark before the Notes chips, spelled through outcomeWord — the one
vocabulary shared with the Lanes chips. The detail page adds one sentence
beside the correction control while a Reader's number stands behind a
failure past the owner window, without naming the Reader. Each Lanes Site
name is a plain link to that Site's failing Series; the outcome chips stay
unlinked, and outcomeChips records why the promise is withdrawn.

backend/internal/web/admin_series_detail.go

@@ -64,6 +64,11 @@ type seriesDetailView struct {
 	// stands. It rides the meta fragment both presses swap, so the answer
 	// itself shows how long the Series has been finished.
 	FinishedSince string
+	// Unverified is the sentence beside the Latest Chapter correction
+	// control while a Reader's number stands behind a failure past the
+	// owner window: the value is unconfirmed and the owner should not trust
+	// it. It never names the Reader. "" otherwise.
+	Unverified string
 }
 
 // adminSeriesDetail renders one Series' page, keyed by the composite
@@ -151,6 +156,14 @@ func (h *Handler) seriesDetailView(a store.AdminSeries) seriesDetailView {
 	v.Corrected = correctedAge(time.Now(), a.LatestCorrectedAt)
 	v.Finished = a.FinishedAt != 0
 	v.FinishedSince = finishedAge(time.Now(), a.FinishedAt)
+	// Unverified: a Reader's number standing behind a failure that has outlived
+	// the owner window is a number nobody has re-checked since — say so next to
+	// the correction control, without naming the Reader. A machine read or a
+	// failure still inside the window carries no sentence; the failure itself
+	// has not yet outlived the twelve hours' worth of trust.
+	if a.RaisedByReader && a.FailureOutcome != "" && a.FailingSince < time.Now().Add(-ownerWindow).UnixMilli() {
+		v.Unverified = "Unverified Reader number: the page has been failing for over 12h, so this Reader-reported chapter is unconfirmed."
+	}
 
 	// Provenance: the actor class behind the current number, evaluated in the
 	// order the classes outrank one another — the owner's stamp, which a