feat(divergence): Jev noul restatement check -> harness review nudge (#25)

nestlog.go

@@ -132,6 +132,32 @@ func (s *MessageStore) FirstClaim(nestID, referentID string) (string, bool) {
 	return "", false
 }
 
+// EarlierDelivers returns the texts of deliver messages answering the same
+// referent, oldest first, excluding the one with id excludeID.
+func (s *MessageStore) EarlierDelivers(nestID, referentID string, excludeID int) []string {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	var out []string
+	for _, m := range s.log[nestID] {
+		if m.Kind == "deliver" && m.RefersTo == referentID && m.ID != excludeID {
+			out = append(out, m.Text)
+		}
+	}
+	return out
+}
+
+// NudgeFor reports whether a nudge already references a given message.
+func (s *MessageStore) NudgeFor(nestID, targetMsgID string) (Message, bool) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	for _, m := range s.log[nestID] {
+		if m.Kind == "nudge" && m.RefersTo == targetMsgID {
+			return m, true
+		}
+	}
+	return Message{}, false
+}
+
 func (s *MessageStore) save(nestID string) error {
 	if err := os.MkdirAll(s.dir, 0o755); err != nil {
 		return err