report: move synthetic ALIAS hop from collector to report view

checker/collect.go

@@ -400,12 +400,6 @@ func observeApex(ctx context.Context, data *AliasData, servers []string, apex st
 
 	if (hasA || hasAAAA) && !data.ApexHasCNAME {
 		data.ApexFlattening = true
-		// Synthesize a pseudo-hop so the report's chain view shows the ALIAS
-		// indirection that would otherwise be invisible from the wire.
-		data.Chain = append(data.Chain, ChainHop{
-			Owner: lowerFQDN(apex),
-			Kind:  KindALIAS,
-		})
 	}
 }
 

checker/report.go

@@ -104,7 +104,15 @@ func buildReportView(data *AliasData, states []sdk.CheckState) *reportView {
 	v.FinalAddresses = append(v.FinalAddresses, data.FinalA...)
 	v.FinalAddresses = append(v.FinalAddresses, data.FinalAAAA...)
 
-	for i, h := range data.Chain {
+	chain := data.Chain
+	if data.ApexFlattening {
+		chain = append(chain, ChainHop{
+			Owner: data.Apex,
+			Kind:  KindALIAS,
+		})
+	}
+
+	for i, h := range chain {
 		step := chainStep{
 			Index:  i + 1,
 			Owner:  h.Owner,
@@ -112,7 +120,7 @@ func buildReportView(data *AliasData, states []sdk.CheckState) *reportView {
 			Target: h.Target,
 			TTL:    h.TTL,
 			Server: h.Server,
-			IsLast: i == len(data.Chain)-1,
+			IsLast: i == len(chain)-1,
 		}
 		switch h.Kind {
 		case KindCNAME: