review: clear stale attribution, gate numberless PUTs, cite the ADR

A Poll finding a higher number now clears series.latest_raised_by: the value
it stores is its own, so the next Poll must not credit that Reader with an
agreement they did not earn, nor charge them for a retraction of a number
they never reported.

A PUT carrying no chapter is no Sighting and defers nothing. The ceiling now
counts the Site's own rest rather than defaultRest. The userscripts PUT an
unchanged read too - the case the whole mechanism exists for was the one they
never sent.

ADR-0011 carries its citations and states honestly when a Reader's marks take
effect.

backend/internal/latest/poller.go

@@ -250,8 +250,8 @@ func (p *Poller) runLanePass(ctx context.Context, name string, paced bool) time.
 		return defaultGap
 	}
 
-	due, err := p.Store.DueForLatestCheck(name,
-		now.Add(-s.Rest).UnixMilli(), now.Add(-sightingCeiling).UnixMilli())
+	due, err := p.Store.DueForLatestCheck(name, now.Add(-s.Rest).UnixMilli(),
+		now.Add(-sightingCeilingRests*s.Rest).UnixMilli())
 	if err != nil {
 		log.Printf("latest poll %s: due query: %v", name, err)
 		st.Gap = defaultGap
@@ -503,6 +503,13 @@ func (p *Poller) judgeSighting(sr store.Series, found float64) {
 	}
 	stored := *sr.LatestChapterNum
 	if found > stored {
+		// The report is neither confirmed nor contradicted, but it is answered:
+		// the value about to be stored is the Poll's own, so leaving the
+		// attribution would credit this Reader with the next Poll's agreement
+		// and blame them if the Site later retracts.
+		if err := p.Store.ClearSightingAttribution(sr.Site, sr.SeriesID, *sr.LatestRaisedBy); err != nil {
+			log.Printf("latest poll %q: clear sighting attribution: %v", sr.Key(), err)
+		}
 		return
 	}
 	if found < stored {