fix(presence): clarify post-migration offline state and emit peer_online events.

After RustDesk→BetterDesk migration, HTTP heartbeats can update last seen while
UDP signal registration is still missing. Show a distinct "No signal" badge,
document the two-channel presence model, and publish peer_online on registration.

betterdesk-server/signal/handler.go

@@ -65,6 +65,19 @@ func signalLimiterKey(kind, clientHost, peerID string) string {
 	return fmt.Sprintf("%s:%s:%s", kind, clientHost, peerID)
 }
 
+func (s *Server) publishPeerOnline(id string) {
+	if s.eventBus == nil {
+		return
+	}
+	s.eventBus.Publish(events.Event{
+		Type: events.EventPeerOnline,
+		Data: map[string]string{
+			"id":     id,
+			"status": "online",
+		},
+	})
+}
+
 func (s *Server) allowRegistration(clientHost, peerID string, knownPeer bool) bool {
 	if s.limiter == nil {
 		return true
@@ -319,6 +332,7 @@ func (s *Server) handleRegisterPeer(msg *pb.RegisterPeer, raddr *net.UDPAddr) {
 
 	log.Printf("[signal] New peer registered: %s from %s (pk_loaded=%v)", id, raddr, len(entry.PK) > 0)
 	s.db.UpdatePeerStatus(id, "ONLINE", raddr.IP.String())
+	s.publishPeerOnline(id)
 }
 
 // handleRegisterPk processes a public key registration.

betterdesk-server/signal/handler_test.go

@@ -9,6 +9,7 @@ import (
 
 	"github.com/unitronix/betterdesk-server/config"
 	"github.com/unitronix/betterdesk-server/db"
+	"github.com/unitronix/betterdesk-server/events"
 	"github.com/unitronix/betterdesk-server/peer"
 	pb "github.com/unitronix/betterdesk-server/proto"
 	"github.com/unitronix/betterdesk-server/ratelimit"
@@ -363,3 +364,27 @@ func TestOrgPolicyForcesRelayOnPunchHole(t *testing.T) {
 		t.Fatal("org block_direct_p2p should force relay")
 	}
 }
+
+func TestPublishPeerOnlineEmitsEvent(t *testing.T) {
+	srv, _ := newTestSignalServer(t, config.EnrollmentModeOpen)
+
+	sub := srv.eventBus.Subscribe(events.EventPeerOnline)
+	defer srv.eventBus.Unsubscribe(sub)
+
+	srv.publishPeerOnline("PEERON1")
+
+	select {
+	case evt := <-sub.Ch:
+		if evt.Type != events.EventPeerOnline {
+			t.Fatalf("event type = %s, want %s", evt.Type, events.EventPeerOnline)
+		}
+		if evt.Data["id"] != "PEERON1" {
+			t.Fatalf("event id = %q, want PEERON1", evt.Data["id"])
+		}
+		if evt.Data["status"] != "online" {
+			t.Fatalf("event status = %q, want online", evt.Data["status"])
+		}
+	case <-time.After(2 * time.Second):
+		t.Fatal("timed out waiting for peer_online event")
+	}
+}

betterdesk-server/signal/ws.go

@@ -336,6 +336,7 @@ func (s *Server) handleRegisterPeerWS(msg *pb.RegisterPeer, remoteAddr string) *
 
 	log.Printf("[signal] New WS peer registered: %s from %s", id, remoteAddr)
 	s.db.UpdatePeerStatus(id, "ONLINE", remoteAddr)
+	s.publishPeerOnline(id)
 
 	return &pb.RendezvousMessage{
 		Union: &pb.RendezvousMessage_RegisterPeerResponse{

docs/troubleshooting/SERVER_MIGRATION.md

@@ -0,0 +1,64 @@
+# RustDesk → BetterDesk server migration — client presence
+
+## Symptom
+
+After replacing a RustDesk Community server (hbbs/hbbr) with BetterDesk while keeping the same IP, keys, and client URLs:
+
+- Remote sessions may work via the relay server.
+- The console shows **Last seen** as recent (e.g. “6 minutes ago”).
+- The **Online** badge stays **Offline** until each client is restarted.
+
+## Why this happens
+
+BetterDesk tracks presence in two separate channels:
+
+| Channel | Client config | Server port | Updates | Console column |
+|---------|---------------|-------------|---------|----------------|
+| HTTP heartbeat | `api_server` | 21114 (`/api/heartbeat`) | DB `last_online`, DB `status` | **Last seen** |
+| UDP registration | `rendezvous_server` / `id_server` | **21116** (`RegisterPeer`) | In-memory `live_online` | **Online / Offline** |
+
+The devices table uses **`live_online`** (signal-server memory map), not the DB `status` field alone.
+
+After migration or a BetterDesk server restart:
+
+1. The in-memory peer table starts **empty** (`SetAllOffline()` on boot).
+2. RustDesk clients often resume **HTTP** heartbeats immediately (same `api_server` URL).
+3. **UDP** registration to port 21116 may stay stale until the client process or service is restarted — even when the hostname/IP did not change.
+
+So “recent last seen + offline” is expected until clients re-register on UDP 21116.
+
+## What to do
+
+1. **Restart** the RustDesk client or its background service on affected machines (or reboot).
+2. No need to regenerate keys if connections already work.
+3. For large fleets, plan a rolling client/service restart after the server backend swap.
+
+## Verify on the server
+
+```bash
+# Signal registration after a client restart
+journalctl -u betterdesk-server -f | grep "New peer registered"
+
+# Compare DB last seen vs live online for one peer
+curl -s -H "X-API-Key: YOUR_KEY" http://127.0.0.1:21114/api/peers/DEVICE_ID | jq '{live_online, last_online, status}'
+```
+
+Checklist:
+
+- [ ] UDP **21116** reachable from clients (firewall, NAT, Docker port mapping).
+- [ ] Enrollment mode is `open`, or migrated peers already exist in the database (`managed` / `locked` can block unknown IDs).
+- [ ] After restart, `live_online` becomes `true` within ~30 seconds.
+
+## Enrollment modes
+
+| Mode | Re-registration after migration |
+|------|-------------------------------|
+| `open` | Any peer with valid keys can register on UDP 21116. |
+| `managed` | Peers already in the DB re-register freely; unknown IDs need approval. |
+| `locked` | Only peers with a valid device token can register. |
+
+## Related
+
+- Go signal handler: `betterdesk-server/signal/handler.go` (UDP `RegisterPeer`)
+- HTTP heartbeat (DB only): `betterdesk-server/api/client_api_handlers.go`
+- Panel mapping: `web-nodejs/services/betterdeskApi.js` (`online: !!peer.live_online`)

web-nodejs/lang/ar.json

@@ -310,7 +310,8 @@
     "group_deleted": "تم حذف مجموعة الأجهزة",
     "folder_group_readonly": "تتم إدارة المجموعات المدعومة بالمجلدات من المجلدات.",
     "manage_user_groups": "إدارة مجموعات المستخدمين",
-    "restore_failed": "فشل استعادة الجهاز"
+    "restore_failed": "فشل استعادة الجهاز",
+    "no_signal_tooltip": "اتصل العميل بـ API مؤخرًا لكنه غير مسجل على خادم الإشارة (UDP :21116). أعد تشغيل العميل بعد ترحيل الخادم."
   },
   "keys": {
     "title": "مفاتيح الخادم",
@@ -732,7 +733,8 @@
     "stopped": "Stopped",
     "unknown": "Unknown",
     "checking": "جارٍ التحقق...",
-    "label": "Status"
+    "label": "Status",
+    "no_signal": "لا إشارة"
   },
   "actions": {
     "refresh": "Refresh",

web-nodejs/lang/cs.json

@@ -303,7 +303,8 @@
     "group_deleted": "Skupina zařízení odstraněna",
     "folder_group_readonly": "Skupiny založené na složkách se spravují ve složkách.",
     "manage_user_groups": "Spravovat skupiny uživatelů",
-    "restore_failed": "Ne udalo sie przywrocic urzadzenia"
+    "restore_failed": "Ne udalo sie przywrocic urzadzenia",
+    "no_signal_tooltip": "Klient nedávno kontaktoval API, ale není zaregistrován na signal serveru (UDP :21116). Po migraci serveru restartujte klienta."
   },
   "keys": {
     "title": "Klíče serveru",
@@ -725,7 +726,8 @@
     "stopped": "Zastaveno",
     "unknown": "Neznámý",
     "checking": "Kontroluji...",
-    "label": "Stav"
+    "label": "Stav",
+    "no_signal": "Bez signálu"
   },
   "actions": {
     "refresh": "Obnovit",

web-nodejs/lang/da.json

@@ -309,7 +309,8 @@
     "group_deleted": "Enhedsgruppen blev slettet",
     "folder_group_readonly": "Mappestøttede grupper administreres fra mapper.",
     "manage_user_groups": "Administrer brugergrupper",
-    "restore_failed": "Enhed konnte nicht wiederhergestellt werden"
+    "restore_failed": "Enhed konnte nicht wiederhergestellt werden",
+    "no_signal_tooltip": "Klienten kontaktede API'et for nylig, men er ikke registreret på signalserveren (UDP :21116). Genstart klienten efter servermigration."
   },
   "keys": {
     "title": "Servernøgler",
@@ -731,7 +732,8 @@
     "stopped": "Stopped",
     "unknown": "Unknown",
     "checking": "Tjekker...",
-    "label": "Status"
+    "label": "Status",
+    "no_signal": "Intet signal"
   },
   "actions": {
     "refresh": "Refresh",

web-nodejs/lang/de.json

@@ -303,7 +303,8 @@
     "group_deleted": "Gerätegruppe gelöscht",
     "folder_group_readonly": "Ordnerbasierte Gruppen werden über Ordner verwaltet.",
     "manage_user_groups": "Benutzergruppen verwalten",
-    "restore_failed": "Gerät konnte nicht wiederhergestellt werden"
+    "restore_failed": "Gerät konnte nicht wiederhergestellt werden",
+    "no_signal_tooltip": "Der Client hat kürzlich die API kontaktiert, ist aber nicht auf dem Signalserver registriert (UDP :21116). Starten Sie den Client nach der Servermigration neu."
   },
   "keys": {
     "title": "Dashboard",
@@ -725,7 +726,8 @@
     "stopped": "Gestoppt",
     "unknown": "Unbekannt",
     "checking": "Prüfe...",
-    "label": "Status"
+    "label": "Status",
+    "no_signal": "Kein Signal"
   },
   "actions": {
     "refresh": "Aktualisieren",

web-nodejs/lang/en.json

@@ -178,6 +178,7 @@
     "filter_online": "Online",
     "filter_offline": "Offline",
     "filter_banned": "Banned",
+    "no_signal_tooltip": "Client contacted the API recently but is not registered on the signal server (UDP :21116). Restart the client after server migration.",
     "selected": "selected",
     "showing": "Showing",
     "of": "of",
@@ -730,6 +731,7 @@
   "status": {
     "online": "Online",
     "offline": "Offline",
+    "no_signal": "No signal",
     "banned": "Banned",
     "running": "Running",
     "stopped": "Stopped",

web-nodejs/lang/es.json

@@ -303,7 +303,8 @@
     "group_deleted": "Grupo de dispositivos eliminado",
     "folder_group_readonly": "Los grupos basados en carpetas se administran desde Carpetas.",
     "manage_user_groups": "Administrar grupos de usuarios",
-    "restore_failed": "Error al restaurar el dispositivo"
+    "restore_failed": "Error al restaurar el dispositivo",
+    "no_signal_tooltip": "El cliente contactó la API recientemente, pero no está registrado en el servidor de señal (UDP :21116). Reinicie el cliente tras la migración del servidor."
   },
   "keys": {
     "title": "Panel",
@@ -725,7 +726,8 @@
     "stopped": "Detenido",
     "unknown": "Desconocido",
     "checking": "Verificando...",
-    "label": "Status"
+    "label": "Status",
+    "no_signal": "Sin señal"
   },
   "actions": {
     "refresh": "Actualizar",

web-nodejs/lang/fi.json

@@ -309,7 +309,8 @@
     "group_deleted": "Laiteryhmä poistettu",
     "folder_group_readonly": "Kansiota tukevia ryhmiä hallitaan kansioista.",
     "manage_user_groups": "Hallinnoi käyttäjäryhmiä",
-    "restore_failed": "Laite konnte nicht wiederhergestellt werden"
+    "restore_failed": "Laite konnte nicht wiederhergestellt werden",
+    "no_signal_tooltip": "Asiakas otti hiljattain yhteyttä API:in, mutta ei ole rekisteröitynyt signal-palvelimeen (UDP :21116). Käynnistä asiakas uudelleen palvelinsiirron jälkeen."
   },
   "keys": {
     "title": "Palvelimen avaimet",
@@ -731,7 +732,8 @@
     "stopped": "Stopped",
     "unknown": "Unknown",
     "checking": "Tarkistetaan...",
-    "label": "Status"
+    "label": "Status",
+    "no_signal": "Ei signaalia"
   },
   "actions": {
     "refresh": "Refresh",

web-nodejs/lang/fr.json

@@ -303,7 +303,8 @@
     "group_deleted": "Groupe d’appareils supprimé",
     "folder_group_readonly": "Les groupes associés aux dossiers sont gérés depuis les dossiers.",
     "manage_user_groups": "Gérer les groupes d’utilisateurs",
-    "restore_failed": "Échec de la restauration de l'appareil"
+    "restore_failed": "Échec de la restauration de l'appareil",
+    "no_signal_tooltip": "Le client a contacté l'API récemment mais n'est pas enregistré sur le serveur de signal (UDP :21116). Redémarrez le client après la migration du serveur."
   },
   "keys": {
     "title": "Tableau de bord",
@@ -725,7 +726,8 @@
     "stopped": "Arrêté",
     "unknown": "Inconnu",
     "checking": "Vérification...",
-    "label": "Status"
+    "label": "Status",
+    "no_signal": "Pas de signal"
   },
   "actions": {
     "refresh": "Actualiser",

web-nodejs/lang/hi.json

@@ -309,7 +309,8 @@
     "group_deleted": "डिवाइस समूह हटा दिया गया",
     "folder_group_readonly": "फ़ोल्डर-समर्थित समूहों को फ़ोल्डरों से प्रबंधित किया जाता है।",
     "manage_user_groups": "उपयोगकर्ता समूह प्रबंधित करें",
-    "restore_failed": "डिवाइस पुनर्स्थापित करने में विफल"
+    "restore_failed": "डिवाइस पुनर्स्थापित करने में विफल",
+    "no_signal_tooltip": "क्लाइंट ने हाल ही में API से संपर्क किया, लेकिन सिग्नल सर्वर (UDP :21116) पर पंजीकृत नहीं है। सर्वर माइग्रेशन के बाद क्लाइंट को पुनः प्रारंभ करें।"
   },
   "keys": {
     "title": "सर्वर कुंजी",
@@ -731,7 +732,8 @@
     "stopped": "Stopped",
     "unknown": "Unknown",
     "checking": "जाँच हो रही है...",
-    "label": "Status"
+    "label": "Status",
+    "no_signal": "कोई सिग्नल नहीं"
   },
   "actions": {
     "refresh": "Refresh",

web-nodejs/lang/hu.json

@@ -309,7 +309,8 @@
     "group_deleted": "Eszközcsoport törölve",
     "folder_group_readonly": "A mappaalapú csoportok kezelése mappákból történik.",
     "manage_user_groups": "Felhasználói csoportok kezelése",
-    "restore_failed": "Eszköz konnte nicht wiederhergestellt werden"
+    "restore_failed": "Eszköz konnte nicht wiederhergestellt werden",
+    "no_signal_tooltip": "Az ügyfél nemrég elérte az API-t, de nincs regisztrálva a jelzőszerveren (UDP :21116). A szerver migrációja után indítsa újra az ügyfelet."
   },
   "keys": {
     "title": "Szerverkulcsok",
@@ -731,7 +732,8 @@
     "stopped": "Stopped",
     "unknown": "Unknown",
     "checking": "Ellenőrzés...",
-    "label": "Status"
+    "label": "Status",
+    "no_signal": "Nincs jel"
   },
   "actions": {
     "refresh": "Refresh",

web-nodejs/lang/id.json

@@ -309,7 +309,8 @@
     "group_deleted": "Grup perangkat dihapus",
     "folder_group_readonly": "Grup yang didukung folder dikelola dari folder.",
     "manage_user_groups": "Kelola grup pengguna",
-    "restore_failed": "Gagal memulihkan perangkat"
+    "restore_failed": "Gagal memulihkan perangkat",
+    "no_signal_tooltip": "Klien baru saja menghubungi API tetapi tidak terdaftar di server sinyal (UDP :21116). Mulai ulang klien setelah migrasi server."
   },
   "keys": {
     "title": "Kunci Server",
@@ -731,7 +732,8 @@
     "stopped": "Stopped",
     "unknown": "Unknown",
     "checking": "Memeriksa...",
-    "label": "Status"
+    "label": "Status",
+    "no_signal": "Tanpa sinyal"
   },
   "actions": {
     "refresh": "Refresh",

web-nodejs/lang/it.json

@@ -303,7 +303,8 @@
     "group_deleted": "Gruppo dispositivi eliminato",
     "folder_group_readonly": "I gruppi basati su cartelle sono gestiti tramite Cartelle.",
     "manage_user_groups": "Gestisci gruppi utente",
-    "restore_failed": "Èchec de la restauration de il dispositivo"
+    "restore_failed": "Èchec de la restauration de il dispositivo",
+    "no_signal_tooltip": "Il client ha contattato l'API di recente ma non è registrato sul server di segnale (UDP :21116). Riavvia il client dopo la migrazione del server."
   },
   "keys": {
     "title": "Chiavi del server",
@@ -725,7 +726,8 @@
     "stopped": "Fermato",
     "unknown": "Sconosciuto",
     "checking": "Verifica...",
-    "label": "Status"
+    "label": "Status",
+    "no_signal": "Nessun segnale"
   },
   "actions": {
     "refresh": "Aggiorna",

web-nodejs/lang/ja.json

@@ -303,7 +303,8 @@
     "group_deleted": "デバイスグループが削除されました",
     "folder_group_readonly": "フォルダーベースのグループはフォルダーから管理されます。",
     "manage_user_groups": "ユーザーグループの管理",
-    "restore_failed": "デバイスの復元に失敗しました"
+    "restore_failed": "デバイスの復元に失敗しました",
+    "no_signal_tooltip": "クライアントは最近 API に接続しましたが、シグナルサーバー (UDP :21116) に登録されていません。サーバー移行後にクライアントを再起動してください。"
   },
   "keys": {
     "title": "サーバーキー",
@@ -725,7 +726,8 @@
     "stopped": "Stopped",
     "unknown": "Unknown",
     "checking": "確認中...",
-    "label": "Status"
+    "label": "Status",
+    "no_signal": "シグナルなし"
   },
   "actions": {
     "refresh": "Refresh",

web-nodejs/lang/ko.json

@@ -303,7 +303,8 @@
     "group_deleted": "기기 그룹이 삭제되었습니다.",
     "folder_group_readonly": "폴더 지원 그룹은 폴더에서 관리됩니다.",
     "manage_user_groups": "사용자 그룹 관리",
-    "restore_failed": "기기 복원에 실패했습니다"
+    "restore_failed": "기기 복원에 실패했습니다",
+    "no_signal_tooltip": "클라이언트가 최근 API에 연락했지만 시그널 서버(UDP :21116)에 등록되지 않았습니다. 서버 마이그레이션 후 클라이언트를 재시작하세요."
   },
   "keys": {
     "title": "서버 키",
@@ -725,7 +726,8 @@
     "stopped": "Stopped",
     "unknown": "Unknown",
     "checking": "확인 중...",
-    "label": "Status"
+    "label": "Status",
+    "no_signal": "신호 없음"
   },
   "actions": {
     "refresh": "Refresh",

web-nodejs/lang/nb.json

@@ -309,7 +309,8 @@
     "group_deleted": "Enhetsgruppe slettet",
     "folder_group_readonly": "Mappestøttede grupper administreres fra mapper.",
     "manage_user_groups": "Administrer brukergrupper",
-    "restore_failed": "Enhet konnte nicht wiederhergestellt werden"
+    "restore_failed": "Enhet konnte nicht wiederhergestellt werden",
+    "no_signal_tooltip": "Klienten kontaktet API-et nylig, men er ikke registrert på signalserveren (UDP :21116). Start klienten på nytt etter servermigrering."
   },
   "keys": {
     "title": "Servernøkler",
@@ -731,7 +732,8 @@
     "stopped": "Stopped",
     "unknown": "Unknown",
     "checking": "Sjekker...",
-    "label": "Status"
+    "label": "Status",
+    "no_signal": "Intet signal"
   },
   "actions": {
     "refresh": "Refresh",

web-nodejs/lang/nl.json

@@ -303,7 +303,8 @@
     "group_deleted": "Apparaatgroep verwijderd",
     "folder_group_readonly": "Mapgebaseerde groepen worden via Mappen beheerd.",
     "manage_user_groups": "Gebruikersgroepen beheren",
-    "restore_failed": "Gerat konnte nicht wiederhergestellt werden"
+    "restore_failed": "Gerat konnte nicht wiederhergestellt werden",
+    "no_signal_tooltip": "De client heeft onlangs de API bereikt maar is niet geregistreerd op de signalserver (UDP :21116). Herstart de client na servermigratie."
   },
   "keys": {
     "title": "Serversleutels",
@@ -725,7 +726,8 @@
     "stopped": "Gestopt",
     "unknown": "Onbekend",
     "checking": "Controleren...",
-    "label": "Status"
+    "label": "Status",
+    "no_signal": "Geen signaal"
   },
   "actions": {
     "refresh": "Vernieuwen",

web-nodejs/lang/pl.json

@@ -303,7 +303,8 @@
       "no_data": "Brak danych o sprzęcie",
       "title": "Informacje sprzętowe",
       "gpu": "Karta graficzna"
-    }
+    },
+    "no_signal_tooltip": "Klient niedawno kontaktował API, ale nie jest zarejestrowany na serwerze sygnałowym (UDP :21116). Uruchom ponownie klienta po migracji serwera."
   },
   "keys": {
     "title": "Klucze serwera",
@@ -735,7 +736,8 @@
     "stopped": "Zatrzymany",
     "unknown": "Nieznany",
     "checking": "Sprawdzanie...",
-    "label": "Status"
+    "label": "Status",
+    "no_signal": "Brak sygnału"
   },
   "actions": {
     "refresh": "Odśwież",

web-nodejs/lang/pt.json

@@ -303,7 +303,8 @@
     "group_deleted": "Grupo de dispositivos excluído",
     "folder_group_readonly": "Grupos baseados em pastas são gerenciados em Pastas.",
     "manage_user_groups": "Gerenciar grupos de usuários",
-    "restore_failed": "Erro al restaurar o dispositivo"
+    "restore_failed": "Erro al restaurar o dispositivo",
+    "no_signal_tooltip": "O cliente contactou a API recentemente, mas não está registado no servidor de sinal (UDP :21116). Reinicie o cliente após a migração do servidor."
   },
   "keys": {
     "title": "Chaves do servidor",
@@ -725,7 +726,8 @@
     "stopped": "Parado",
     "unknown": "Desconhecido",
     "checking": "A verificar...",
-    "label": "Status"
+    "label": "Status",
+    "no_signal": "Sem sinal"
   },
   "actions": {
     "refresh": "Atualizar",

web-nodejs/lang/ro.json

@@ -309,7 +309,8 @@
     "group_deleted": "Grupul de dispozitive a fost șters",
     "folder_group_readonly": "Grupurile susținute de foldere sunt gestionate din dosare.",
     "manage_user_groups": "Gestionați grupurile de utilizatori",
-    "restore_failed": "Dispozitiv konnte nicht wiederhergestellt werden"
+    "restore_failed": "Dispozitiv konnte nicht wiederhergestellt werden",
+    "no_signal_tooltip": "Clientul a contactat API-ul recent, dar nu este înregistrat pe serverul de semnal (UDP :21116). Reporniți clientul după migrarea serverului."
   },
   "keys": {
     "title": "Cheile serverului",
@@ -731,7 +732,8 @@
     "stopped": "Stopped",
     "unknown": "Unknown",
     "checking": "Se verifică...",
-    "label": "Status"
+    "label": "Status",
+    "no_signal": "Fără semnal"
   },
   "actions": {
     "refresh": "Refresh",

web-nodejs/lang/sv.json

@@ -309,7 +309,8 @@
     "group_deleted": "Enhetsgruppen har tagits bort",
     "folder_group_readonly": "Mappstödda grupper hanteras från mappar.",
     "manage_user_groups": "Hantera användargrupper",
-    "restore_failed": "Enhet konnte nicht wiederhergestellt werden"
+    "restore_failed": "Enhet konnte nicht wiederhergestellt werden",
+    "no_signal_tooltip": "Klienten kontaktade API:et nyligen men är inte registrerad på signalservern (UDP :21116). Starta om klienten efter servermigrering."
   },
   "keys": {
     "title": "Servernycklar",
@@ -731,7 +732,8 @@
     "stopped": "Stopped",
     "unknown": "Unknown",
     "checking": "Kontrollerar...",
-    "label": "Status"
+    "label": "Status",
+    "no_signal": "Ingen signal"
   },
   "actions": {
     "refresh": "Refresh",

web-nodejs/lang/th.json

@@ -309,7 +309,8 @@
     "group_deleted": "ลบกลุ่มอุปกรณ์แล้ว",
     "folder_group_readonly": "กลุ่มที่สำรองโฟลเดอร์ได้รับการจัดการจากโฟลเดอร์",
     "manage_user_groups": "จัดการกลุ่มผู้ใช้",
-    "restore_failed": "กู้คืนอุปกรณ์ไม่สำเร็จ"
+    "restore_failed": "กู้คืนอุปกรณ์ไม่สำเร็จ",
+    "no_signal_tooltip": "ไคลเอนต์ติดต่อ API เมื่อเร็ว ๆ นี้ แต่ยังไม่ได้ลงทะเบียนบนเซิร์ฟเวอร์สัญญาณ (UDP :21116) โปรดรีสตาร์ทไคลเอนต์หลังย้ายเซิร์ฟเวอร์"
   },
   "keys": {
     "title": "คีย์เซิร์ฟเวอร์",
@@ -731,7 +732,8 @@
     "stopped": "Stopped",
     "unknown": "Unknown",
     "checking": "กำลังตรวจสอบ...",
-    "label": "Status"
+    "label": "Status",
+    "no_signal": "ไม่มีสัญญาณ"
   },
   "actions": {
     "refresh": "Refresh",

web-nodejs/lang/tr.json

@@ -309,7 +309,8 @@
     "group_deleted": "Cihaz grubu silindi",
     "folder_group_readonly": "Klasör destekli gruplar klasörlerden yönetilir.",
     "manage_user_groups": "Kullanıcı gruplarını yönet",
-    "restore_failed": "Cihaz geri yükleme başarısız"
+    "restore_failed": "Cihaz geri yükleme başarısız",
+    "no_signal_tooltip": "İstemci yakın zamanda API ile iletişim kurdu ancak sinyal sunucusuna (UDP :21116) kayıtlı değil. Sunucu geçişinden sonra istemciyi yeniden başlatın."
   },
   "keys": {
     "title": "Sunucu Anahtarları",
@@ -731,7 +732,8 @@
     "stopped": "Stopped",
     "unknown": "Unknown",
     "checking": "Kontrol ediliyor...",
-    "label": "Status"
+    "label": "Status",
+    "no_signal": "Sinyal yok"
   },
   "actions": {
     "refresh": "Refresh",

web-nodejs/lang/uk.json

@@ -309,7 +309,8 @@
     "group_deleted": "Групу пристроїв видалено",
     "folder_group_readonly": "Групи з папками керуються з папок.",
     "manage_user_groups": "Керуйте групами користувачів",
-    "restore_failed": "Пристрій konnte nicht wiederhergestellt werden"
+    "restore_failed": "Пристрій konnte nicht wiederhergestellt werden",
+    "no_signal_tooltip": "Клієнт нещодавно звернувся до API, але не зареєстрований на сигнальному сервері (UDP :21116). Перезапустіть клієнт після міграції сервера."
   },
   "keys": {
     "title": "Ключі сервера",
@@ -731,7 +732,8 @@
     "stopped": "Stopped",
     "unknown": "Unknown",
     "checking": "Перевірка...",
-    "label": "Status"
+    "label": "Status",
+    "no_signal": "Немає сигналу"
   },
   "actions": {
     "refresh": "Refresh",

web-nodejs/lang/vi.json

@@ -309,7 +309,8 @@
     "group_deleted": "Đã xóa nhóm thiết bị",
     "folder_group_readonly": "Các nhóm được hỗ trợ bởi thư mục được quản lý từ các thư mục.",
     "manage_user_groups": "Quản lý nhóm người dùng",
-    "restore_failed": "Không thể khôi phục thiết bị"
+    "restore_failed": "Không thể khôi phục thiết bị",
+    "no_signal_tooltip": "Máy khách vừa liên hệ API nhưng chưa đăng ký trên máy chủ tín hiệu (UDP :21116). Khởi động lại máy khách sau khi di chuyển máy chủ."
   },
   "keys": {
     "title": "Khóa máy chủ",
@@ -731,7 +732,8 @@
     "stopped": "Stopped",
     "unknown": "Unknown",
     "checking": "Đang kiểm tra...",
-    "label": "Status"
+    "label": "Status",
+    "no_signal": "Không có tín hiệu"
   },
   "actions": {
     "refresh": "Refresh",

web-nodejs/lang/zh-TW.json

@@ -303,7 +303,8 @@
     "group_deleted": "裝置群組已刪除",
     "folder_group_readonly": "資料夾關聯的群組由資料夾管理。",
     "manage_user_groups": "管理使用者群組",
-    "restore_failed": "還原裝置失敗"
+    "restore_failed": "還原裝置失敗",
+    "no_signal_tooltip": "用戶端最近聯絡了 API，但未在訊號伺服器（UDP :21116）上註冊。伺服器遷移後請重新啟動用戶端。"
   },
   "keys": {
     "title": "伺服器金鑰",
@@ -735,7 +736,8 @@
     "stopped": "已停止",
     "unknown": "未知",
     "checking": "檢查中...",
-    "label": "Status"
+    "label": "Status",
+    "no_signal": "無信號"
   },
   "actions": {
     "refresh": "重新整理",

web-nodejs/lang/zh.json

@@ -303,7 +303,8 @@
     "group_deleted": "设备分组已删除",
     "folder_group_readonly": "文件夹关联的分组由文件夹管理。",
     "manage_user_groups": "管理用户组",
-    "restore_failed": "恢复设备失败"
+    "restore_failed": "恢复设备失败",
+    "no_signal_tooltip": "客户端最近联系了 API，但未在信号服务器（UDP :21116）上注册。服务器迁移后请重启客户端。"
   },
   "keys": {
     "title": "服务器密钥",
@@ -725,7 +726,8 @@
     "stopped": "已停止",
     "unknown": "未知",
     "checking": "检查中...",
-    "label": "Status"
+    "label": "Status",
+    "no_signal": "无信号"
   },
   "actions": {
     "refresh": "刷新",

web-nodejs/public/css/device-detail.css

@@ -177,6 +177,15 @@
     background: var(--text-tertiary, #6e7681);
 }
 
+.device-panel-status-badge.no_signal {
+    background: var(--accent-yellow-muted, rgba(210, 153, 34, 0.15));
+    color: var(--accent-yellow, #d29922);
+}
+
+.device-panel-status-badge.no_signal .status-dot {
+    background: var(--accent-yellow, #d29922);
+}
+
 .device-panel-status-badge.banned {
     background: var(--accent-red-muted, rgba(248, 81, 73, 0.15));
     color: var(--accent-red, #f85149);

web-nodejs/public/css/devices.css

@@ -638,6 +638,10 @@ td.column-hidden {
     background: var(--text-tertiary, #6e7681);
 }
 
+.device-status-dot.no_signal {
+    background: var(--accent-yellow, #d29922);
+}
+
 .device-status-dot.banned {
     background: var(--accent-red, #f85149);
 }
@@ -717,6 +721,15 @@ td.column-hidden {
     color: var(--text-tertiary);
 }
 
+.status-badge.no_signal {
+    background: var(--accent-yellow-muted, rgba(210, 153, 34, 0.15));
+    color: var(--accent-yellow, #d29922);
+}
+
+.status-badge.no_signal .status-dot {
+    background: var(--accent-yellow, #d29922);
+}
+
 .status-badge.banned {
     background: var(--accent-red-muted);
     color: var(--accent-red);

web-nodejs/public/js/deviceDetail.js

@@ -143,15 +143,35 @@ const DeviceDetail = (function () {
 
     // ── Header ──
 
+    function _resolveDeviceStatus(d) {
+        if (d.banned) {
+            return { className: 'banned', label: _('status.banned'), title: '' };
+        }
+        if (d.online) {
+            const tier = (d.status_tier || 'online').toLowerCase();
+            if (tier === 'degraded' || tier === 'critical') {
+                return { className: tier, label: _('status.' + tier), title: '' };
+            }
+            return { className: 'online', label: _('status.online'), title: '' };
+        }
+        if (d.no_signal) {
+            return {
+                className: 'no_signal',
+                label: _('status.no_signal'),
+                title: _('devices.no_signal_tooltip')
+            };
+        }
+        return { className: 'offline', label: _('status.offline'), title: '' };
+    }
+
     function _headerHTML() {
         const d = device;
         const platformLabel = d.platform || d.os || '-';
         const platformIcon = Utils.getPlatformIcon(d.platform || d.os);
-        const statusRaw = (d.status_tier || (d.online ? 'online' : 'offline')).toLowerCase();
-        const statusClass = d.banned ? 'banned' : statusRaw;
-        const statusLabel = d.banned
-            ? _('status.banned')
-            : (_('status.' + statusRaw));
+        const statusInfo = _resolveDeviceStatus(d);
+        const statusClass = statusInfo.className;
+        const statusLabel = statusInfo.label;
+        const statusTitle = statusInfo.title;
 
         return `
         <div class="device-panel-header">
@@ -174,7 +194,7 @@ const DeviceDetail = (function () {
                 </button>
             </div>
             <div class="device-panel-status-bar">
-                <span class="device-panel-status-badge ${statusClass}">
+                <span class="device-panel-status-badge ${statusClass}"${statusTitle ? ` title="${Utils.escapeHtml(statusTitle)}"` : ''}>
                     <span class="status-dot"></span>${statusLabel}
                 </span>
                 <span class="device-panel-platform-badge">
@@ -1301,15 +1321,16 @@ const DeviceDetail = (function () {
                     // Only re-render header status (minimal update, avoid losing form state)
                     const statusBar = overlayEl.querySelector('.device-panel-status-bar');
                     if (statusBar) {
-                        const statusRaw2 = (device.status_tier || (device.online ? 'online' : 'offline')).toLowerCase();
-                        const statusClass = device.banned ? 'banned' : statusRaw2;
-                        const statusLabel = device.banned
-                            ? _('status.banned')
-                            : (_('status.' + statusRaw2));
+                        const statusInfo = _resolveDeviceStatus(device);
                         const badge = statusBar.querySelector('.device-panel-status-badge');
                         if (badge) {
-                            badge.className = 'device-panel-status-badge ' + statusClass;
-                            badge.innerHTML = '<span class="status-dot"></span>' + statusLabel;
+                            badge.className = 'device-panel-status-badge ' + statusInfo.className;
+                            if (statusInfo.title) {
+                                badge.title = statusInfo.title;
+                            } else {
+                                badge.removeAttribute('title');
+                            }
+                            badge.innerHTML = '<span class="status-dot"></span>' + statusInfo.label;
                         }
                     }
                 }

web-nodejs/public/js/devices.js

@@ -12,6 +12,23 @@
         return '#808080';
     }
 
+    function deviceStatusInfo(d) {
+        if (d.banned) {
+            return { className: 'banned', label: _('status.banned'), title: '' };
+        }
+        if (d.online) {
+            return { className: 'online', label: _('status.online'), title: '' };
+        }
+        if (d.no_signal) {
+            return {
+                className: 'no_signal',
+                label: _('status.no_signal'),
+                title: _('devices.no_signal_tooltip')
+            };
+        }
+        return { className: 'offline', label: _('status.offline'), title: '' };
+    }
+
     // Map device_type to Material Icons
     function getDeviceTypeIcon(type) {
         switch ((type || '').toLowerCase()) {
@@ -147,7 +164,7 @@
         if (!row) return;
 
         const normalizedStatus = String(status || '').toLowerCase();
-        const statusClassName = ['online', 'offline', 'degraded', 'critical'].includes(normalizedStatus)
+        const statusClassName = ['online', 'offline', 'no_signal', 'degraded', 'critical'].includes(normalizedStatus)
             ? normalizedStatus
             : 'offline';
         const statusText = _('status.' + statusClassName);
@@ -173,6 +190,7 @@
             dev.live_status = statusClassName;
             dev.live_online = statusClassName === 'online';
             dev.online = statusClassName === 'online';
+            dev.no_signal = statusClassName === 'no_signal';
         }
     }
 
@@ -472,12 +490,10 @@
             return;
         }
         
-        const statusClass = (d) => d.banned ? 'banned' : d.online ? 'online' : 'offline';
-        const statusLabel = (d) => d.banned ? _('status.banned') : d.online ? _('status.online') : _('status.offline');
-
         tableBody.innerHTML = pageDevices.map(device => {
             const eid = Utils.escapeHtml(device.id);
-            const sc = statusClass(device);
+            const statusInfo = deviceStatusInfo(device);
+            const sc = statusInfo.className;
             return `
             <tr data-id="${eid}" class="${device.banned ? 'banned-row' : ''}" draggable="true">
                 <td data-column="id">
@@ -506,7 +522,7 @@
                     <span class="last-seen-text" title="${Utils.formatDate(device.last_online)}">${Utils.formatRelativeTime(device.last_online)}</span>
                 </td>
                 <td data-column="status">
-                    <span class="status-badge ${sc}"><span class="status-dot"></span>${statusLabel(device)}</span>
+                    <span class="status-badge ${sc}"${statusInfo.title ? ` title="${Utils.escapeHtml(statusInfo.title)}"` : ''}><span class="status-dot"></span>${statusInfo.label}</span>
                 </td>
                 <td data-column="tags">${renderTagsCell(device)}</td>
                 <td data-column="actions">
@@ -905,7 +921,7 @@
                     </div>
                     <div class="detail-row">
                         <span class="detail-label">${_('status.label')}:</span>
-                        <span class="detail-value">${device.banned ? _('status.banned') : device.online ? _('status.online') : _('status.offline')}</span>
+                        <span class="detail-value">${deviceStatusInfo(device).label}</span>
                     </div>
                     <div class="detail-row">
                         <span class="detail-label">${_('devices.last_online')}:</span>

web-nodejs/services/betterdeskApi.js

@@ -462,9 +462,21 @@ async function syncOnlineStatus(/* db */) {
  *   online (bool), banned (bool), created_at, last_online, ban_reason,
  *   folder_id, tags[], status_tier, uuid, disabled, os, version
  */
+const NO_SIGNAL_THRESHOLD_MS = 5 * 60 * 1000;
+
+function isRecentLastOnline(lastOnline) {
+    if (!lastOnline) return false;
+    const t = new Date(lastOnline).getTime();
+    return Number.isFinite(t) && (Date.now() - t) < NO_SIGNAL_THRESHOLD_MS;
+}
+
 function normalisePeer(peer) {
     if (!peer) return peer;
 
+    const liveOnline = !!(peer.live_online);
+    const banned = !!(peer.banned);
+    const lastOnline = peer.last_online || '';
+
     // Parse tags: Go server sends comma-separated string or JSON array
     let tags = [];
     if (Array.isArray(peer.tags)) {
@@ -488,10 +500,11 @@ function normalisePeer(peer) {
         version: peer.version || '',
         ip: peer.ip || '',
         note: peer.note || '',
-        online: !!(peer.live_online),
-        banned: !!(peer.banned),
+        online: liveOnline,
+        banned,
+        no_signal: !liveOnline && !banned && isRecentLastOnline(lastOnline),
         created_at: peer.created_at || '',
-        last_online: peer.last_online || '',
+        last_online: lastOnline,
         ban_reason: peer.ban_reason || '',
         banned_at: peer.banned_at || null,
         folder_id: peer.folder_id || null,