fix(repeater-liveness): address issue #755 review feedback

cmd/ingestor/main.go

@@ -222,12 +222,31 @@ func handleMessage(store *Store, tag string, source MQTTSource, m mqtt.Message,
 		}
 	}
 
+	// Status topic: meshcore/<region>/<observer_id>/status
+	// Checked BEFORE JSON parse — non-JSON or malformed payloads must still update last_seen (#463)
+	if len(parts) >= 4 && parts[3] == "status" {
+		observerID := parts[2]
+		iata := parts[1]
+		var name string
+		var meta *ObserverMeta
+		var statusMsg map[string]interface{}
+		if json.Unmarshal(m.Payload(), &statusMsg) == nil {
+			name, _ = statusMsg["origin"].(string)
+			meta = extractObserverMeta(statusMsg)
+		}
+		if err := store.UpsertObserver(observerID, name, iata, meta); err != nil {
+			log.Printf("MQTT [%s] observer status error: %v", tag, err)
+		}
+		log.Printf("MQTT [%s] status: %s (%s)", tag, firstNonEmpty(name, observerID), iata)
+		return
+	}
+
 	var msg map[string]interface{}
 	if err := json.Unmarshal(m.Payload(), &msg); err != nil {
 		return
 	}
 
-	// Skip status/connection topics
+	// Skip global status/connection topics
 	if topic == "meshcore/status" || topic == "meshcore/events/connection" {
 		return
 	}
@@ -261,6 +280,7 @@ func handleMessage(store *Store, tag string, source MQTTSource, m mqtt.Message,
 		return
 	}
 
+
 	// Format 1: Raw packet (meshcoretomqtt / Cisien format)
 	rawHex, _ := msg["raw"].(string)
 	if rawHex != "" {

cmd/ingestor/main_test.go

@@ -201,6 +201,28 @@ func TestHandleMessageStatusTopic(t *testing.T) {
 	}
 }
 
+// #463: status messages with non-JSON payloads must still update last_seen.
+// Some firmware versions may send plain-text or binary status payloads.
+func TestHandleMessageStatusNonJSONPayload(t *testing.T) {
+	store := newTestStore(t)
+	source := MQTTSource{Name: "test"}
+	msg := &mockMessage{
+		topic:   "meshcore/SJC/obs1/status",
+		payload: []byte(`not json`),
+	}
+
+	handleMessage(store, "test", source, msg, nil, nil)
+
+	var lastSeen string
+	err := store.db.QueryRow("SELECT last_seen FROM observers WHERE id = 'obs1'").Scan(&lastSeen)
+	if err != nil {
+		t.Fatalf("observer not found after non-JSON status: %v", err)
+	}
+	if lastSeen == "" {
+		t.Error("last_seen should be set even for non-JSON status payloads")
+	}
+}
+
 func TestHandleMessageSkipStatusTopics(t *testing.T) {
 	store := newTestStore(t)
 	source := MQTTSource{Name: "test"}

cmd/server/neighbor_persist.go

@@ -496,6 +496,12 @@ func backfillResolvedPathsAsync(store *PacketStore, dbPath string, chunkSize int
 					affectedSet[r.txHash] = true
 					if tx, ok := store.byHash[r.txHash]; ok {
 						pickBestObservation(tx)
+						// tx.ResolvedPath is now updated; add newly resolved pubkeys to
+						// the relay time index. The first call during buildPathHopIndex
+						// was a no-op (ResolvedPath was nil then), so no duplicates.
+						if ms, err := time.Parse(time.RFC3339, tx.FirstSeen); err == nil {
+							addTxToRelayTimeIndex(store.relayTimes, tx, ms.UnixMilli())
+						}
 					}
 				}
 			}