DLV-R1: a verdict below the picture's revision asks the verdicts' first view again, unless the picture holds it

ADR 0615 §5: a gap in revisions asks the first view once more. The indexer's verdict events carry no mark of when its
verdicts were made, so verdicts made again show only as revisions starting low, which the grants part passed over as
already held. A redelivery of a verdict the picture holds for its manifest is still passed over, so a consumer's backlog
after a restart asks nothing.

Claude-Session: https://claude.ai/code/session_01JG73KJNrH5EgFXMKKYSrig

modules/mesh-grants/grants_test.go

@@ -2444,6 +2444,16 @@ func TestGrants(t *testing.T) {
 		if v := verdictOf(); !v.Refused() || !slices.Equal(v.Problems, []string{"p"}) || verdicts.Status().Asks != asked {
 			t.Errorf("manifest-refused, then a revision already held: %+v, asks %d (was %d)", v, verdicts.Status().Asks, asked)
 		}
+		// A revision below the picture's (ADR 0615 §5; the verdicts made again restart low): the same verdict again is a
+		// redelivery, passed over; another verdict asks the first view once more.
+		heard(delivery.ManifestRefusedEvent, delivery.ManifestRefused{V: 1, Module: "mod-z", Digest: digest, Judge: "j", Problems: []string{"p"}, Revision: 3})
+		if verdicts.Status().Asks != asked {
+			t.Errorf("a held verdict redelivered at a lower revision asked: asks %d (was %d)", verdicts.Status().Asks, asked)
+		}
+		heard(delivery.ManifestAcceptedEvent, delivery.ManifestAccepted{V: 1, Module: "mod-z", Digest: digest, Judge: "j", Revision: 2})
+		waitFor(t, func() bool { return verdicts.Status().Asks > asked })
+		waitFor(t, func() bool { s := verdicts.Status(); return !s.Answered.Before(s.Asked) })
+		asked = verdicts.Status().Asks
 		heard(delivery.ManifestAcceptedEvent, delivery.ManifestAccepted{V: 1, Module: "mod-z", Digest: digest, Judge: "j"})
 		waitFor(t, func() bool { return verdicts.Status().Asks > asked })
 		asked = verdicts.Status().Asks

modules/mesh-grants/internal/grants/firstviews.go

@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"slices"
 	"sort"
 	"strings"
 	"sync"
@@ -259,6 +260,18 @@ func (v *Views) HearVerdict(ctx context.Context, event string, data []byte, logf
 		}
 		return gap(fmt.Sprintf("the indexer's %s of %s at revision %d names no manifest", event, verdict.Module, revision))
 	}
+	// A revision below the picture's is a gap (ADR 0615 §5): the verdict events carry no mark of when the indexer's verdicts
+	// were made, so one made again shows only as revisions starting low. A redelivery of a verdict the picture already
+	// holds for its manifest is passed over, so a consumer's backlog after a restart asks nothing.
+	if revision < held.Revision {
+		if raw, found := f.Get(key); found {
+			if was, err := delivery.DecodeManifestVerdict(raw); err == nil && sameVerdict(was, verdict) {
+				return nil
+			}
+		}
+		return gap(fmt.Sprintf("the indexer's %s of %s at revision %d, below the picture's %d: its verdicts were made again, or this verdict was missed",
+			event, verdict.Module, revision, held.Revision))
+	}
 	value, err := json.Marshal(verdict)
 	if err != nil {
 		return err
@@ -270,6 +283,11 @@ func (v *Views) HearVerdict(ctx context.Context, event string, data []byte, logf
 	return nil
 }
 
+// sameVerdict says two verdicts of one manifest say the same: its module, accepted or refused, the judge and the problems.
+func sameVerdict(a, b delivery.ManifestVerdict) bool {
+	return a.Module == b.Module && a.State == b.State && a.Judge == b.Judge && slices.Equal(a.Problems, b.Problems)
+}
+
 // unansweredCondition is FirstViewUnanswered for one first view, raised or cleared.
 func unansweredCondition(fv FirstView, s views.Status, raised bool) asks.Condition {
 	c := asks.Condition{Key: FirstViewUnanswered + "." + fv.Owner + "." + fv.State, Subject: asks.Scope{Scope: "module", ID: Module}}