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unlinked, and outcomeChips records why the promise is withdrawn.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/templates/series-detail.html

@@ -19,6 +19,7 @@
       <input type="number" name="chapter" step="any" placeholder="{{.Chapter}}" required>
       <button type="submit" class="ghost">Set</button>
     </div>
+    {{if .Unverified}}<p class="hint">{{.Unverified}}</p>{{end}}
   </form>
   <form class="dform" hx-post="/admin/series/{{.Key}}/series-url" hx-target="#detail-meta" hx-swap="outerHTML">
     <h3>Repair series URL</h3>