Merge remote-tracking branch 'origin/main' into ez_group_dropdown3

# Conflicts:
#	lib/main.dart

.swift-version

@@ -0,0 +1 @@
+6.2.4

lib/connector/meshcore_connector.dart

@@ -19,6 +19,7 @@ import '../services/message_retry_service.dart';
 import '../services/path_history_service.dart';
 import '../services/app_settings_service.dart';
 import '../services/background_service.dart';
+import '../services/timeout_prediction_service.dart';
 import '../services/notification_service.dart';
 import 'meshcore_connector_usb.dart';
 import 'meshcore_connector_tcp.dart';
@@ -166,6 +167,10 @@ class MeshCoreConnector extends ChangeNotifier {
   bool _isLoadingContacts = false;
   bool _isLoadingChannels = false;
   bool _hasLoadedChannels = false;
+  TimeoutPredictionService? _timeoutPredictionService;
+  // Intentionally global (not per-contact): tracks overall network activity.
+  // Frequent RX from any source indicates a busy network with more collisions.
+  DateTime _lastRxTime = DateTime.now();
   bool _batteryRequested = false;
   bool _awaitingSelfInfo = false;
   bool _hasReceivedDeviceInfo = false;
@@ -199,6 +204,9 @@ class MeshCoreConnector extends ChangeNotifier {
   int _queueSyncRetries = 0;
   static const int _maxQueueSyncRetries = 3;
   static const int _queueSyncTimeoutMs = 5000; // 5 second timeout
+  // Serializes path operations (setContactPath/clearContactPath) to prevent
+  // interleaved async calls from leaving in-memory state inconsistent with device.
+  Future<void> _pathOpLock = Future.value();
   Map<String, String>? _currentCustomVars;
 
   // Channel syncing state (sequential pattern)
@@ -558,6 +566,10 @@ class MeshCoreConnector extends ChangeNotifier {
       _unreadStore.saveContactUnreadCount(
         Map<String, int>.from(_contactUnreadCount),
       );
+      _notificationService.clearContactNotification(
+        contactKeyHex,
+        getTotalUnreadCount(),
+      );
       notifyListeners();
     }
   }
@@ -576,6 +588,10 @@ class MeshCoreConnector extends ChangeNotifier {
           _channels.isNotEmpty ? _channels : _cachedChannels,
         ),
       );
+      _notificationService.clearChannelNotification(
+        channelIndex,
+        getTotalUnreadCount(),
+      );
       notifyListeners();
     }
   }
@@ -657,6 +673,7 @@ class MeshCoreConnector extends ChangeNotifier {
     BleDebugLogService? bleDebugLogService,
     AppDebugLogService? appDebugLogService,
     BackgroundService? backgroundService,
+    TimeoutPredictionService? timeoutPredictionService,
   }) {
     _retryService = retryService;
     _pathHistoryService = pathHistoryService;
@@ -664,6 +681,7 @@ class MeshCoreConnector extends ChangeNotifier {
     _bleDebugLogService = bleDebugLogService;
     _appDebugLogService = appDebugLogService;
     _backgroundService = backgroundService;
+    _timeoutPredictionService = timeoutPredictionService;
     _usbManager.setDebugLogService(_appDebugLogService);
     _tcpConnector.setDebugLogService(_appDebugLogService);
 
@@ -678,13 +696,28 @@ class MeshCoreConnector extends ChangeNotifier {
       updateMessageCallback: _updateMessage,
       clearContactPathCallback: clearContactPath,
       setContactPathCallback: setContactPath,
-      calculateTimeoutCallback: (pathLength, messageBytes) =>
+      calculateTimeoutCallback:
-          calculateTimeout(pathLength: pathLength, messageBytes: messageBytes),
+          (pathLength, messageBytes, {String? contactKey}) => calculateTimeout(
+            pathLength: pathLength,
+            messageBytes: messageBytes,
+            contactKey: contactKey,
+          ),
       getSelfPublicKeyCallback: () => _selfPublicKey,
       prepareContactOutboundTextCallback: prepareContactOutboundText,
       appSettingsService: appSettingsService,
       debugLogService: _appDebugLogService,
       recordPathResultCallback: _recordPathResult,
+      onDeliveryObservedCallback:
+          (contactKey, pathLength, messageBytes, tripTimeMs) {
+            final secSinceRx = DateTime.now().difference(_lastRxTime).inSeconds;
+            _timeoutPredictionService?.recordObservation(
+              contactKey: contactKey,
+              pathLength: pathLength,
+              messageBytes: messageBytes,
+              tripTimeMs: tripTimeMs,
+              secondsSinceLastRx: secSinceRx,
+            );
+          },
     );
   }
 
@@ -1740,18 +1773,33 @@ class MeshCoreConnector extends ChangeNotifier {
     Uint8List customPath,
     int pathLen,
   ) async {
-    if (!isConnected) return;
+    // Serialize path operations to prevent interleaved async calls from
+    // leaving in-memory state inconsistent with the device.
+    final prev = _pathOpLock;
+    final completer = Completer<void>();
+    _pathOpLock = completer.future;
+    await prev;
+    try {
+      if (!isConnected) return;
 
-    await sendFrame(
+      await sendFrame(
-      buildUpdateContactPathFrame(
+        buildUpdateContactPathFrame(
-        contact.publicKey,
+          contact.publicKey,
-        customPath,
+          customPath,
-        pathLen,
+          pathLen,
-        type: contact.type,
+          type: contact.type,
-        flags: contact.flags,
+          flags: contact.flags,
-        name: contact.name,
+          name: contact.name,
-      ),
+        ),
-    );
+      );
+      // USB writes return instantly (no BLE flow control), so give the firmware
+      // time to persist the path change before subsequent commands.
+      if (_activeTransport == MeshCoreTransportType.usb) {
+        await Future<void>.delayed(const Duration(milliseconds: 100));
+      }
+    } finally {
+      completer.complete();
+    }
   }
 
   Future<void> setContactFavorite(Contact contact, bool isFavorite) async {
@@ -2136,25 +2184,34 @@ class MeshCoreConnector extends ChangeNotifier {
   }
 
   Future<void> clearContactPath(Contact contact) async {
-    if (!isConnected) return;
+    // Serialize path operations to prevent interleaved async calls.
+    final prev = _pathOpLock;
+    final completer = Completer<void>();
+    _pathOpLock = completer.future;
+    await prev;
+    try {
+      if (!isConnected) return;
 
-    await sendFrame(buildResetPathFrame(contact.publicKey));
+      await sendFrame(buildResetPathFrame(contact.publicKey));
-    final existingIndex = _contacts.indexWhere(
+      if (_activeTransport == MeshCoreTransportType.usb) {
-      (c) => c.publicKeyHex == contact.publicKeyHex,
+        await Future<void>.delayed(const Duration(milliseconds: 100));
-    );
+      }
-    if (existingIndex >= 0) {
+      final existingIndex = _contacts.indexWhere(
-      final existing = _contacts[existingIndex];
+        (c) => c.publicKeyHex == contact.publicKeyHex,
-      // Use copyWith to preserve pathOverride and pathOverrideBytes
-      _contacts[existingIndex] = existing.copyWith(
-        pathOverride: null,
-        pathOverrideBytes: null,
-        pathLength: -1,
-        path: Uint8List(0),
       );
-      notifyListeners();
+      if (existingIndex >= 0) {
-      unawaited(_persistContacts());
+        final existing = _contacts[existingIndex];
+        // Preserve pathOverride and pathOverrideBytes — only reset device path
+        _contacts[existingIndex] = existing.copyWith(
+          pathLength: -1,
+          path: Uint8List(0),
+        );
+        notifyListeners();
+        unawaited(_persistContacts());
+      }
+    } finally {
+      completer.complete();
     }
-    // The device will send updated contact info with path_len = -1
   }
 
   void updateContactInMemory(
@@ -2463,6 +2520,7 @@ class MeshCoreConnector extends ChangeNotifier {
 
   void _handleFrame(List<int> data) {
     if (data.isEmpty) return;
+    _lastRxTime = DateTime.now();
 
     final frame = Uint8List.fromList(data);
     _receivedFramesController.add(frame);
@@ -2490,6 +2548,9 @@ class MeshCoreConnector extends ChangeNotifier {
         _isLoadingContacts = true;
         notifyListeners();
         break;
+      case pushCodeAdvert:
+        // Known contact was seen again - just a pub key, no action needed
+        break;
       case pushCodeNewAdvert:
         debugPrint('Got New CONTACT');
         // It's the same format as respCodeContact, so we can reuse the handler
@@ -2836,38 +2897,68 @@ class MeshCoreConnector extends ChangeNotifier {
     }
   }
 
-  /// Calculate timeout for a message based on radio settings and path length
+  /// Estimate single-packet airtime in ms from radio settings, or a fallback.
-  /// Returns timeout in milliseconds, considering number of hops
+  int _estimateAirtimeMs(int messageBytes) {
-  int calculateTimeout({required int pathLength, int messageBytes = 100}) {
-    // If we have radio settings, use them for accurate calculation
     if (_currentFreqHz != null &&
         _currentBwHz != null &&
         _currentSf != null &&
         _currentCr != null) {
       final cr = _currentCr! <= 4 ? _currentCr! : _currentCr! - 4;
-      return calculateMessageTimeout(
+      return calculateLoRaAirtime(
-        freqHz: _currentFreqHz!,
+        payloadBytes: messageBytes,
-        bwHz: _currentBwHz!,
+        spreadingFactor: _currentSf!,
-        sf: _currentSf!,
+        bandwidthHz: _currentBwHz!,
-        cr: cr,
+        codingRate: cr,
-        pathLength: pathLength,
+        lowDataRateOptimize: _currentSf! >= 11,
-        messageBytes: messageBytes,
       );
     }
+    return 50; // fallback: ~SF7/BW125 for 100 bytes
+  }
 
-    // Fallback: Conservative estimates based on typical settings
+  /// Physics-based worst-case timeout (ceiling).
-    // Assume SF7, BW125, which gives ~50ms airtime for 100 bytes
+  int _physicsMaxTimeout(int pathLength, int airtime) {
-    const estimatedAirtime = 50;
-
     if (pathLength < 0) {
-      // Flood mode: Base delay + 16× airtime
+      return 500 + (16 * airtime);
-      return 500 + (16 * estimatedAirtime);
     } else {
-      // Direct path: Base delay + ((airtime×6 + 250ms)×(hops+1))
+      return 500 + ((airtime * 6 + 250) * (pathLength + 1));
-      return 500 + ((estimatedAirtime * 6 + 250) * (pathLength + 1));
     }
   }
 
+  /// Physics-based minimum timeout (floor): raw traversal time.
+  int _physicsMinTimeout(int pathLength, int airtime) {
+    if (pathLength < 0) {
+      return airtime;
+    } else {
+      return airtime * (pathLength + 1);
+    }
+  }
+
+  /// Calculate timeout for a message based on radio settings and path length.
+  /// Returns timeout in milliseconds, considering number of hops.
+  int calculateTimeout({
+    required int pathLength,
+    int messageBytes = 100,
+    String? contactKey,
+  }) {
+    final airtime = _estimateAirtimeMs(messageBytes);
+    final physicsMin = _physicsMinTimeout(pathLength, airtime);
+    final physicsMax = _physicsMaxTimeout(pathLength, airtime);
+
+    // Try ML-based prediction, clamped between physics bounds
+    final secSinceRx = DateTime.now().difference(_lastRxTime).inSeconds;
+    final mlTimeout = _timeoutPredictionService?.predictTimeout(
+      contactKey: contactKey,
+      pathLength: pathLength,
+      messageBytes: messageBytes,
+      secondsSinceLastRx: secSinceRx,
+    );
+    if (mlTimeout != null) {
+      return mlTimeout.clamp(physicsMin, physicsMax);
+    }
+
+    return physicsMax;
+  }
+
   void _handleContact(Uint8List frame, {bool isContact = true}) {
     final contact = Contact.fromFrame(frame);
     if (contact != null) {

lib/l10n/app_bg.arb

@@ -1888,5 +1888,6 @@
   "tcpErrorUnsupported": "Транспортът чрез TCP не се поддържа на тази платформа.",
   "tcpErrorTimedOut": "Връзката TCP изтекла.",
   "tcpConnectionFailed": "Неуспешно е установено TCP връзката: {error}",
-  "map_showDiscoveryContacts": "Покажи контакти за откриване"
+  "map_showDiscoveryContacts": "Покажи контакти за откриване",
+  "map_setAsMyLocation": "Задайте като моя местоположение"
 }

lib/l10n/app_de.arb

@@ -1916,5 +1916,6 @@
   "tcpErrorUnsupported": "Die TCP-Übertragung wird auf dieser Plattform nicht unterstützt.",
   "tcpErrorTimedOut": "Die TCP-Verbindung ist abgelaufen.",
   "tcpConnectionFailed": "Fehler beim TCP-Verbindungsaufbau: {error}",
-  "map_showDiscoveryContacts": "Entdeckungs-Kontakte anzeigen"
+  "map_showDiscoveryContacts": "Entdeckungs-Kontakte anzeigen",
+  "map_setAsMyLocation": "Als meine aktuelle Position festlegen"
 }

lib/l10n/app_en.arb

@@ -808,6 +808,7 @@
   "map_source": "Source",
   "map_flags": "Flags",
   "map_shareMarkerHere": "Share marker here",
+  "map_setAsMyLocation": "Set as my location",
   "map_pinLabel": "Pin label",
   "map_label": "Label",
   "map_pointOfInterest": "Point of interest",

lib/l10n/app_es.arb

@@ -1916,5 +1916,6 @@
   "tcpErrorUnsupported": "El protocolo de transporte TCP no está soportado en esta plataforma.",
   "tcpErrorTimedOut": "La conexión TCP ha caducado.",
   "tcpConnectionFailed": "Error en la conexión TCP: {error}",
-  "map_showDiscoveryContacts": "Mostrar Contactos de Descubrimiento"
+  "map_showDiscoveryContacts": "Mostrar Contactos de Descubrimiento",
+  "map_setAsMyLocation": "Establecer mi ubicación"
 }

lib/l10n/app_fr.arb

@@ -1888,5 +1888,6 @@
   "tcpErrorUnsupported": "Le protocole TCP n'est pas pris en charge sur cette plateforme.",
   "tcpErrorTimedOut": "La connexion TCP a expiré.",
   "tcpConnectionFailed": "Échec de la connexion TCP : {error}",
-  "map_showDiscoveryContacts": "Afficher les contacts de découverte"
+  "map_showDiscoveryContacts": "Afficher les contacts de découverte",
+  "map_setAsMyLocation": "Définir comme ma localisation"
 }

lib/l10n/app_it.arb

@@ -1888,5 +1888,6 @@
   "tcpErrorUnsupported": "Il protocollo TCP non è supportato su questa piattaforma.",
   "tcpErrorTimedOut": "La connessione TCP è scaduta.",
   "tcpConnectionFailed": "Impossibile stabilire la connessione TCP: {error}",
-  "map_showDiscoveryContacts": "Mostra Contatti di Discovery"
+  "map_showDiscoveryContacts": "Mostra Contatti di Discovery",
+  "map_setAsMyLocation": "Imposta come la mia posizione"
 }

lib/l10n/app_localizations.dart

@@ -2752,6 +2752,12 @@ abstract class AppLocalizations {
   /// **'Share marker here'**
   String get map_shareMarkerHere;
 
+  /// No description provided for @map_setAsMyLocation.
+  ///
+  /// In en, this message translates to:
+  /// **'Set as my location'**
+  String get map_setAsMyLocation;
+
   /// No description provided for @map_pinLabel.
   ///
   /// In en, this message translates to:

lib/l10n/app_localizations_bg.dart

@@ -1514,6 +1514,9 @@ class AppLocalizationsBg extends AppLocalizations {
   @override
   String get map_shareMarkerHere => 'Споделете маркер тук';
 
+  @override
+  String get map_setAsMyLocation => 'Задайте като моя местоположение';
+
   @override
   String get map_pinLabel => 'Етикетиране на пин';
 

lib/l10n/app_localizations_de.dart

@@ -1516,6 +1516,9 @@ class AppLocalizationsDe extends AppLocalizations {
   @override
   String get map_shareMarkerHere => 'Teilen Sie den Marker hier.';
 
+  @override
+  String get map_setAsMyLocation => 'Als meine aktuelle Position festlegen';
+
   @override
   String get map_pinLabel => 'Pin Name';
 

lib/l10n/app_localizations_en.dart

@@ -1490,6 +1490,9 @@ class AppLocalizationsEn extends AppLocalizations {
   @override
   String get map_shareMarkerHere => 'Share marker here';
 
+  @override
+  String get map_setAsMyLocation => 'Set as my location';
+
   @override
   String get map_pinLabel => 'Pin label';
 

lib/l10n/app_localizations_es.dart

@@ -1513,6 +1513,9 @@ class AppLocalizationsEs extends AppLocalizations {
   @override
   String get map_shareMarkerHere => 'Compartir marcador aquí';
 
+  @override
+  String get map_setAsMyLocation => 'Establecer mi ubicación';
+
   @override
   String get map_pinLabel => 'Etiqueta de marcador';
 

lib/l10n/app_localizations_fr.dart

@@ -1521,6 +1521,9 @@ class AppLocalizationsFr extends AppLocalizations {
   @override
   String get map_shareMarkerHere => 'Partager le marqueur ici';
 
+  @override
+  String get map_setAsMyLocation => 'Définir comme ma localisation';
+
   @override
   String get map_pinLabel => 'Étiquete de repin';
 

lib/l10n/app_localizations_it.dart

@@ -1513,6 +1513,9 @@ class AppLocalizationsIt extends AppLocalizations {
   @override
   String get map_shareMarkerHere => 'Condividi marcatore qui';
 
+  @override
+  String get map_setAsMyLocation => 'Imposta come la mia posizione';
+
   @override
   String get map_pinLabel => 'Etichetta PIN';
 

lib/l10n/app_localizations_nl.dart

@@ -1505,6 +1505,9 @@ class AppLocalizationsNl extends AppLocalizations {
   @override
   String get map_shareMarkerHere => 'Deel marker hier';
 
+  @override
+  String get map_setAsMyLocation => 'Stel dit in als mijn locatie';
+
   @override
   String get map_pinLabel => 'Label vastzetten';
 

lib/l10n/app_localizations_pl.dart

@@ -1515,6 +1515,9 @@ class AppLocalizationsPl extends AppLocalizations {
   @override
   String get map_shareMarkerHere => 'Udostępnij znacznik tutaj';
 
+  @override
+  String get map_setAsMyLocation => 'Ustaw jako moje lokalizację';
+
   @override
   String get map_pinLabel => 'Oznacz etykietę';
 

lib/l10n/app_localizations_pt.dart

@@ -1514,6 +1514,9 @@ class AppLocalizationsPt extends AppLocalizations {
   @override
   String get map_shareMarkerHere => 'Compartilhar marcador aqui';
 
+  @override
+  String get map_setAsMyLocation => 'Defina minha localização';
+
   @override
   String get map_pinLabel => 'Rótulo de marcador';
 

lib/l10n/app_localizations_ru.dart

@@ -1516,6 +1516,9 @@ class AppLocalizationsRu extends AppLocalizations {
   @override
   String get map_shareMarkerHere => 'Поделиться меткой здесь';
 
+  @override
+  String get map_setAsMyLocation => 'Установить мое местоположение';
+
   @override
   String get map_pinLabel => 'Метка';
 

lib/l10n/app_localizations_sk.dart

@@ -1507,6 +1507,9 @@ class AppLocalizationsSk extends AppLocalizations {
   @override
   String get map_shareMarkerHere => 'Zdieľte značku tu';
 
+  @override
+  String get map_setAsMyLocation => 'Nastavte ako moju polohu';
+
   @override
   String get map_pinLabel => 'Označka upozornenia';
 

lib/l10n/app_localizations_sl.dart

@@ -1501,6 +1501,9 @@ class AppLocalizationsSl extends AppLocalizations {
   @override
   String get map_shareMarkerHere => 'Delite točke tukaj.';
 
+  @override
+  String get map_setAsMyLocation => 'Nastavite to kot mojo lokacijo';
+
   @override
   String get map_pinLabel => 'Oznaka za pritrditev';
 

lib/l10n/app_localizations_sv.dart

@@ -1497,6 +1497,9 @@ class AppLocalizationsSv extends AppLocalizations {
   @override
   String get map_shareMarkerHere => 'Dela markeringen här';
 
+  @override
+  String get map_setAsMyLocation => 'Ange som min plats';
+
   @override
   String get map_pinLabel => 'Fästetikett';
 

lib/l10n/app_localizations_uk.dart

@@ -1513,6 +1513,9 @@ class AppLocalizationsUk extends AppLocalizations {
   @override
   String get map_shareMarkerHere => 'Поділитися маркером тут';
 
+  @override
+  String get map_setAsMyLocation => 'Встановити моє місцезнаходження';
+
   @override
   String get map_pinLabel => 'Мітка піна';
 

lib/l10n/app_localizations_zh.dart

@@ -1424,6 +1424,9 @@ class AppLocalizationsZh extends AppLocalizations {
   @override
   String get map_shareMarkerHere => '在此分享标记';
 
+  @override
+  String get map_setAsMyLocation => '设置为我的位置';
+
   @override
   String get map_pinLabel => '标签';
 

lib/l10n/app_nl.arb

@@ -1888,5 +1888,6 @@
   "tcpErrorUnsupported": "TCP-transport wordt niet ondersteund op deze platform.",
   "tcpErrorTimedOut": "De TCP-verbinding is verlopen.",
   "tcpConnectionFailed": "Verbinding met TCP mislukt: {error}",
-  "map_showDiscoveryContacts": "Ontdek contacten weergeven"
+  "map_showDiscoveryContacts": "Ontdek contacten weergeven",
+  "map_setAsMyLocation": "Stel dit in als mijn locatie"
 }

lib/l10n/app_pl.arb

@@ -1888,5 +1888,6 @@
   "tcpErrorUnsupported": "Transport protokoł TCP nie jest obsługiwany na tym urządzeniu.",
   "tcpErrorTimedOut": "Połączenie TCP zakończyło się bez powodzenia.",
   "tcpConnectionFailed": "Błąd połączenia TCP: {error}",
-  "map_showDiscoveryContacts": "Pokaż kontakty odkrywania"
+  "map_showDiscoveryContacts": "Pokaż kontakty odkrywania",
+  "map_setAsMyLocation": "Ustaw jako moje lokalizację"
 }

lib/l10n/app_pt.arb

@@ -1888,5 +1888,6 @@
   "tcpErrorUnsupported": "O protocolo TCP não é suportado nesta plataforma.",
   "tcpErrorTimedOut": "A conexão TCP expirou.",
   "tcpConnectionFailed": "Falha na conexão TCP: {error}",
-  "map_showDiscoveryContacts": "Mostrar Contatos de Descoberta"
+  "map_showDiscoveryContacts": "Mostrar Contatos de Descoberta",
+  "map_setAsMyLocation": "Defina minha localização"
 }

lib/l10n/app_ru.arb

@@ -1128,5 +1128,6 @@
   "tcpErrorUnsupported": "Протокол TCP не поддерживается на этой платформе.",
   "tcpErrorTimedOut": "Соединение TCP не удалось установить.",
   "tcpConnectionFailed": "Не удалось установить соединение TCP: {error}",
-  "map_showDiscoveryContacts": "Показать контакты Discovery"
+  "map_showDiscoveryContacts": "Показать контакты Discovery",
+  "map_setAsMyLocation": "Установить мое местоположение"
 }

lib/l10n/app_sk.arb

@@ -1888,5 +1888,6 @@
   "tcpErrorUnsupported": "Prevoz prostredníctvom protokolu TCP nie je na tejto platforme podporovaný.",
   "tcpErrorTimedOut": "Pripojenie TCP vypršalo.",
   "tcpConnectionFailed": "Neúspešné vytvorenie TCP spojenia: {error}",
-  "map_showDiscoveryContacts": "Zobraziť kontakty objavov"
+  "map_showDiscoveryContacts": "Zobraziť kontakty objavov",
+  "map_setAsMyLocation": "Nastavte ako moju polohu"
 }

lib/l10n/app_sl.arb

@@ -1888,5 +1888,6 @@
   "tcpErrorUnsupported": "Transport preko protokola TCP ni podprt na tej platformi.",
   "tcpErrorTimedOut": "Povezava TCP je presegla časovno obdobje.",
   "tcpConnectionFailed": "Napaka pri povezavi TCP: {error}",
-  "map_showDiscoveryContacts": "Prikaži odkritja kontaktov"
+  "map_showDiscoveryContacts": "Prikaži odkritja kontaktov",
+  "map_setAsMyLocation": "Nastavite to kot mojo lokacijo"
 }

lib/l10n/app_sv.arb

@@ -1888,5 +1888,6 @@
   "tcpErrorUnsupported": "TCP-transport fungerar inte på denna plattform.",
   "tcpErrorTimedOut": "TCP-anslutningen har tidsut gått.",
   "tcpConnectionFailed": "Fel vid TCP-anslutning: {error}",
-  "map_showDiscoveryContacts": "Visa Discovery-kontakter"
+  "map_showDiscoveryContacts": "Visa Discovery-kontakter",
+  "map_setAsMyLocation": "Ange som min plats"
 }

lib/l10n/app_uk.arb

@@ -1888,5 +1888,6 @@
   "tcpErrorUnsupported": "Транспорт TCP не підтримується на цій платформі.",
   "tcpErrorTimedOut": "З'єднання TCP завершилося через закінчення часу очікування.",
   "tcpConnectionFailed": "Не вдалося встановити з'єднання TCP: {error}",
-  "map_showDiscoveryContacts": "Показати контакти Відкриття"
+  "map_showDiscoveryContacts": "Показати контакти Відкриття",
+  "map_setAsMyLocation": "Встановити моє місцезнаходження"
 }

lib/l10n/app_zh.arb

@@ -1893,5 +1893,6 @@
   "tcpErrorUnsupported": "此平台不支持 TCP 传输。",
   "tcpErrorTimedOut": "TCP 连接超时。",
   "tcpConnectionFailed": "TCP 连接失败：{error}",
-  "map_showDiscoveryContacts": "显示发现联系人"
+  "map_showDiscoveryContacts": "显示发现联系人",
+  "map_setAsMyLocation": "设置为我的位置"
 }

lib/main.dart

@@ -20,6 +20,7 @@ import 'services/background_service.dart';
 import 'services/map_tile_cache_service.dart';
 import 'services/chat_text_scale_service.dart';
 import 'services/ui_view_state_service.dart';
+import 'services/timeout_prediction_service.dart';
 import 'storage/prefs_manager.dart';
 import 'utils/app_logger.dart';
 
@@ -41,6 +42,7 @@ void main() async {
   final mapTileCacheService = MapTileCacheService();
   final chatTextScaleService = ChatTextScaleService();
   final uiViewStateService = UiViewStateService();
+  final timeoutPredictionService = TimeoutPredictionService(storage);
 
   // Load settings
   await appSettingsService.loadSettings();
@@ -59,6 +61,7 @@ void main() async {
 
   await chatTextScaleService.initialize();
   await uiViewStateService.initialize();
+  await timeoutPredictionService.initialize();
 
   // Wire up connector with services
   connector.initialize(
@@ -68,6 +71,7 @@ void main() async {
     bleDebugLogService: bleDebugLogService,
     appDebugLogService: appDebugLogService,
     backgroundService: backgroundService,
+    timeoutPredictionService: timeoutPredictionService,
   );
 
   await connector.loadContactCache();
@@ -90,6 +94,7 @@ void main() async {
       mapTileCacheService: mapTileCacheService,
       chatTextScaleService: chatTextScaleService,
       uiViewStateService: uiViewStateService,
+      timeoutPredictionService: timeoutPredictionService,
     ),
   );
 }
@@ -126,6 +131,7 @@ class MeshCoreApp extends StatelessWidget {
   final MapTileCacheService mapTileCacheService;
   final ChatTextScaleService chatTextScaleService;
   final UiViewStateService uiViewStateService;
+  final TimeoutPredictionService timeoutPredictionService;
 
   const MeshCoreApp({
     super.key,
@@ -139,6 +145,7 @@ class MeshCoreApp extends StatelessWidget {
     required this.mapTileCacheService,
     required this.chatTextScaleService,
     required this.uiViewStateService,
+    required this.timeoutPredictionService,
   });
 
   @override
@@ -155,6 +162,7 @@ class MeshCoreApp extends StatelessWidget {
         ChangeNotifierProvider.value(value: uiViewStateService),
         Provider.value(value: storage),
         Provider.value(value: mapTileCacheService),
+        ChangeNotifierProvider.value(value: timeoutPredictionService),
       ],
       child: Consumer<AppSettingsService>(
         builder: (context, settingsService, child) {

lib/models/delivery_observation.dart

@@ -0,0 +1,43 @@
+class DeliveryObservation {
+  final String contactKey;
+  final int pathLength;
+  final int messageBytes;
+  final int secondsSinceLastRx;
+  final bool isFlood;
+  final int deliveryMs;
+  final DateTime timestamp;
+
+  DeliveryObservation({
+    required this.contactKey,
+    required this.pathLength,
+    required this.messageBytes,
+    required this.secondsSinceLastRx,
+    required this.isFlood,
+    required this.deliveryMs,
+    required this.timestamp,
+  });
+
+  Map<String, dynamic> toJson() {
+    return {
+      'contact_key': contactKey,
+      'path_length': pathLength,
+      'message_bytes': messageBytes,
+      'seconds_since_last_rx': secondsSinceLastRx,
+      'is_flood': isFlood,
+      'delivery_ms': deliveryMs,
+      'timestamp': timestamp.toIso8601String(),
+    };
+  }
+
+  factory DeliveryObservation.fromJson(Map<String, dynamic> json) {
+    return DeliveryObservation(
+      contactKey: json['contact_key'] as String,
+      pathLength: json['path_length'] as int,
+      messageBytes: json['message_bytes'] as int,
+      secondsSinceLastRx: json['seconds_since_last_rx'] as int? ?? 0,
+      isFlood: json['is_flood'] as bool,
+      deliveryMs: json['delivery_ms'] as int,
+      timestamp: DateTime.parse(json['timestamp'] as String),
+    );
+  }
+}

lib/screens/chat_screen.dart

@@ -106,10 +106,9 @@ class _ChatScreenState extends State<ChatScreen> {
             final unreadLabel = context.l10n.chat_unread(unreadCount);
             final pathLabel = _currentPathLabel(contact);
 
-            // Show path details if we have path data (from device or override)
+            // Show path details if we have non-empty path data (from device or override)
-            final hasPathData =
-                contact.path.isNotEmpty || contact.pathOverrideBytes != null;
             final effectivePath = contact.pathOverrideBytes ?? contact.path;
+            final hasPathData = effectivePath.isNotEmpty;
 
             return Column(
               crossAxisAlignment: CrossAxisAlignment.start,
@@ -143,12 +142,25 @@ class _ChatScreenState extends State<ChatScreen> {
               final contact = _resolveContact(connector);
               final isFloodMode = contact.pathOverride == -1;
 
+              final isDirectMode = contact.pathOverride == 0;
+              final activeMode = isFloodMode
+                  ? 'flood'
+                  : isDirectMode
+                  ? 'direct'
+                  : 'auto';
+
               return PopupMenuButton<String>(
                 icon: Icon(isFloodMode ? Icons.waves : Icons.route),
                 tooltip: context.l10n.chat_routingMode,
                 onSelected: (mode) async {
                   if (mode == 'flood') {
                     await connector.setPathOverride(contact, pathLen: -1);
+                  } else if (mode == 'direct') {
+                    await connector.setPathOverride(
+                      contact,
+                      pathLen: 0,
+                      pathBytes: Uint8List(0),
+                    );
                   } else {
                     await connector.setPathOverride(contact, pathLen: null);
                   }
@@ -161,7 +173,7 @@ class _ChatScreenState extends State<ChatScreen> {
                         Icon(
                           Icons.auto_mode,
                           size: 20,
-                          color: !isFloodMode
+                          color: activeMode == 'auto'
                               ? Theme.of(context).primaryColor
                               : null,
                         ),
@@ -169,7 +181,30 @@ class _ChatScreenState extends State<ChatScreen> {
                         Text(
                           context.l10n.chat_autoUseSavedPath,
                           style: TextStyle(
-                            fontWeight: !isFloodMode
+                            fontWeight: activeMode == 'auto'
+                                ? FontWeight.bold
+                                : FontWeight.normal,
+                          ),
+                        ),
+                      ],
+                    ),
+                  ),
+                  PopupMenuItem(
+                    value: 'direct',
+                    child: Row(
+                      children: [
+                        Icon(
+                          Icons.near_me,
+                          size: 20,
+                          color: activeMode == 'direct'
+                              ? Theme.of(context).primaryColor
+                              : null,
+                        ),
+                        const SizedBox(width: 8),
+                        Text(
+                          context.l10n.chat_direct,
+                          style: TextStyle(
+                            fontWeight: activeMode == 'direct'
                                 ? FontWeight.bold
                                 : FontWeight.normal,
                           ),
@@ -184,7 +219,7 @@ class _ChatScreenState extends State<ChatScreen> {
                         Icon(
                           Icons.waves,
                           size: 20,
-                          color: isFloodMode
+                          color: activeMode == 'flood'
                               ? Theme.of(context).primaryColor
                               : null,
                         ),
@@ -192,7 +227,7 @@ class _ChatScreenState extends State<ChatScreen> {
                         Text(
                           context.l10n.chat_forceFloodMode,
                           style: TextStyle(
-                            fontWeight: isFloodMode
+                            fontWeight: activeMode == 'flood'
                                 ? FontWeight.bold
                                 : FontWeight.normal,
                           ),
@@ -251,7 +286,9 @@ class _ChatScreenState extends State<ChatScreen> {
           ),
           const SizedBox(height: 8),
           Text(
-            context.l10n.chat_sendMessageTo(widget.contact.name),
+            context.l10n.chat_sendMessageTo(
+              _resolveContact(context.read<MeshCoreConnector>()).name,
+            ),
             style: TextStyle(fontSize: 14, color: Colors.grey[500]),
           ),
         ],
@@ -269,6 +306,7 @@ class _ChatScreenState extends State<ChatScreen> {
 
     // Auto-scroll to bottom if user is already at bottom
     WidgetsBinding.instance.addPostFrameCallback((_) {
+      if (!mounted) return;
       _scrollController.scrollToBottomIfAtBottom();
     });
 
@@ -293,10 +331,10 @@ class _ChatScreenState extends State<ChatScreen> {
             );
           }
           final messageIndex = index;
-          Contact contact = widget.contact;
+          Contact contact = _resolveContact(connector);
           final message = reversedMessages[messageIndex];
           String fourByteHex = '';
-          if (widget.contact.type == advTypeRoom) {
+          if (contact.type == advTypeRoom) {
             contact = _resolveContactFrom4Bytes(
               connector,
               message.fourByteRoomContactKey.isEmpty
@@ -314,12 +352,13 @@ class _ChatScreenState extends State<ChatScreen> {
               final textScale = context.select<ChatTextScaleService, double>(
                 (service) => service.scale,
               );
+              final resolvedContact = _resolveContact(connector);
               return _MessageBubble(
                 message: message,
-                senderName: widget.contact.type == advTypeRoom
+                senderName: resolvedContact.type == advTypeRoom
                     ? "${contact.name} [$fourByteHex]"
                     : contact.name,
-                isRoomServer: widget.contact.type == advTypeRoom,
+                isRoomServer: resolvedContact.type == advTypeRoom,
                 textScale: textScale,
                 onTap: () => _openMessagePath(message, contact),
                 onLongPress: () => _showMessageActions(message, contact),
@@ -457,7 +496,7 @@ class _ChatScreenState extends State<ChatScreen> {
       return;
     }
 
-    connector.sendMessage(widget.contact, text);
+    connector.sendMessage(_resolveContact(connector), text);
     _textController.clear();
     _textFieldFocusNode.requestFocus();
   }
@@ -654,7 +693,7 @@ class _ChatScreenState extends State<ChatScreen> {
 
                                 // Set the path override to persist user's choice
                                 await connector.setPathOverride(
-                                  widget.contact,
+                                  _resolveContact(connector),
                                   pathLen: pathLength,
                                   pathBytes: pathBytes,
                                 );
@@ -663,7 +702,7 @@ class _ChatScreenState extends State<ChatScreen> {
                                 Navigator.pop(context);
                                 await _notifyPathSet(
                                   connector,
-                                  widget.contact,
+                                  _resolveContact(connector),
                                   pathBytes,
                                   path.hopCount,
                                 );
@@ -722,7 +761,9 @@ class _ChatScreenState extends State<ChatScreen> {
                         style: const TextStyle(fontSize: 11),
                       ),
                       onTap: () async {
-                        await connector.clearContactPath(widget.contact);
+                        await connector.clearContactPath(
+                          _resolveContact(connector),
+                        );
                         if (!context.mounted) return;
                         ScaffoldMessenger.of(context).showSnackBar(
                           SnackBar(
@@ -750,7 +791,7 @@ class _ChatScreenState extends State<ChatScreen> {
                       ),
                       onTap: () async {
                         await connector.setPathOverride(
-                          widget.contact,
+                          _resolveContact(connector),
                           pathLen: -1,
                         );
                         if (!context.mounted) return;
@@ -1005,11 +1046,7 @@ class _ChatScreenState extends State<ChatScreen> {
     );
 
     if (result == null) {
-      appLogger.info(
+      return; // Cancelled — keep existing path
-        'PathSelectionDialog was cancelled or returned null',
-        tag: 'ChatScreen',
-      );
-      return;
     }
 
     if (!mounted) {
@@ -1025,14 +1062,19 @@ class _ChatScreenState extends State<ChatScreen> {
       tag: 'ChatScreen',
     );
     await connector.setPathOverride(
-      widget.contact,
+      _resolveContact(connector),
       pathLen: result.length,
       pathBytes: result,
     );
     appLogger.info('setPathOverride completed', tag: 'ChatScreen');
 
     if (!mounted) return;
-    await _notifyPathSet(connector, widget.contact, result, result.length);
+    await _notifyPathSet(
+      connector,
+      _resolveContact(connector),
+      result,
+      result.length,
+    );
   }
 
   void _openMessagePath(Message message, Contact contact) {
@@ -1044,10 +1086,10 @@ class _ChatScreenState extends State<ChatScreen> {
     final String senderName;
     if (message.isOutgoing) {
       senderName = connector.selfName ?? context.l10n.chat_me;
-    } else if (widget.contact.type == advTypeRoom) {
+    } else if (_resolveContact(connector).type == advTypeRoom) {
       senderName = "${contact.name} [$fourByteHex]";
     } else {
-      senderName = widget.contact.name;
+      senderName = _resolveContact(connector).name;
     }
     final pathMessage = ChannelMessage(
       senderKey: null,
@@ -1110,7 +1152,8 @@ class _ChatScreenState extends State<ChatScreen> {
                   _retryMessage(message);
                 },
               ),
-            if (widget.contact.type == advTypeRoom)
+            if (_resolveContact(context.read<MeshCoreConnector>()).type ==
+                advTypeRoom)
               ListTile(
                 leading: const Icon(Icons.chat),
                 title: Text(context.l10n.contacts_openChat),
@@ -1148,7 +1191,7 @@ class _ChatScreenState extends State<ChatScreen> {
   void _retryMessage(Message message) {
     final connector = Provider.of<MeshCoreConnector>(context, listen: false);
     // Retry using the contact's current path override setting
-    connector.sendMessage(widget.contact, message.text);
+    connector.sendMessage(_resolveContact(connector), message.text);
     ScaffoldMessenger.of(
       context,
     ).showSnackBar(SnackBar(content: Text(context.l10n.chat_retryingMessage)));
@@ -1174,7 +1217,8 @@ class _ChatScreenState extends State<ChatScreen> {
 
     // For room servers, include sender name (like channels) since multiple users
     // For 1:1 chats, sender is implicit (null)
-    final senderName = widget.contact.type == advTypeRoom
+    final liveContact = _resolveContact(connector);
+    final senderName = liveContact.type == advTypeRoom
         ? senderContact.name
         : null;
     final hash = ReactionHelper.computeReactionHash(
@@ -1183,7 +1227,7 @@ class _ChatScreenState extends State<ChatScreen> {
       message.text,
     );
     final reactionText = 'r:$hash:$emojiIndex';
-    connector.sendMessage(widget.contact, reactionText);
+    connector.sendMessage(_resolveContact(connector), reactionText);
   }
 }
 

lib/screens/contacts_screen.dart

@@ -3,6 +3,7 @@ import 'dart:async';
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 import 'package:meshcore_open/screens/path_trace_map.dart';
+import 'package:meshcore_open/services/notification_service.dart';
 import 'package:meshcore_open/utils/app_logger.dart';
 import 'package:meshcore_open/widgets/app_bar.dart';
 import 'package:provider/provider.dart';
@@ -66,6 +67,13 @@ class _ContactsScreenState extends State<ContactsScreen>
         .contactsSearchText;
     _loadGroups();
     _setupFrameListener();
+    _clearAdvertNotifications();
+  }
+
+  void _clearAdvertNotifications() {
+    final connector = context.read<MeshCoreConnector>();
+    final contactIds = connector.contacts.map((c) => c.publicKeyHex).toList();
+    NotificationService().clearAdvertNotifications(contactIds);
   }
 
   @override

lib/screens/map_screen.dart

@@ -1509,6 +1509,23 @@ class _MapScreenState extends State<MapScreen> {
                 );
               },
             ),
+            ListTile(
+              leading: const Icon(Icons.my_location),
+              title: Text(context.l10n.map_setAsMyLocation),
+              onTap: () async {
+                final messenger = ScaffoldMessenger.of(context);
+                final successMsg = context.l10n.settings_locationUpdated;
+                Navigator.pop(sheetContext);
+                if (!connector.isConnected) return;
+                await connector.setNodeLocation(
+                  lat: position.latitude,
+                  lon: position.longitude,
+                );
+                await connector.refreshDeviceInfo();
+                if (!mounted) return;
+                messenger.showSnackBar(SnackBar(content: Text(successMsg)));
+              },
+            ),
             ListTile(
               leading: const Icon(Icons.close),
               title: Text(context.l10n.common_cancel),

lib/services/message_retry_service.dart

@@ -44,6 +44,12 @@ class MessageRetryService extends ChangeNotifier {
       []; // Rolling buffer of recent ACK hashes
   final Map<String, List<String>> _pendingMessageQueuePerContact =
       {}; // contactPubKeyHex → FIFO queue of messageIds (DEPRECATED - will be removed)
+  final Map<String, List<String>> _sendQueue =
+      {}; // contactPubKeyHex → ordered list of messageIds awaiting send
+  final Set<String> _activeMessages =
+      {}; // messageIds currently in-flight (sent/retrying)
+  final Set<String> _resolvedMessages =
+      {}; // messageIds already resolved (prevents double _onMessageResolved)
   final Map<String, String> _expectedHashToMessageId =
       {}; // expectedAckHashHex → messageId (for matching RESP_CODE_SENT by hash)
 
@@ -52,12 +58,13 @@ class MessageRetryService extends ChangeNotifier {
   Function(Message)? _updateMessageCallback;
   Function(Contact)? _clearContactPathCallback;
   Function(Contact, Uint8List, int)? _setContactPathCallback;
-  Function(int, int)? _calculateTimeoutCallback;
+  Function(int, int, {String? contactKey})? _calculateTimeoutCallback;
   Uint8List? Function()? _getSelfPublicKeyCallback;
   String Function(Contact, String)? _prepareContactOutboundTextCallback;
   AppSettingsService? _appSettingsService;
   AppDebugLogService? _debugLogService;
   Function(String, PathSelection, bool, int?)? _recordPathResultCallback;
+  Function(String, int, int, int)? _onDeliveryObservedCallback;
 
   MessageRetryService();
 
@@ -67,12 +74,20 @@ class MessageRetryService extends ChangeNotifier {
     required Function(Message) updateMessageCallback,
     Function(Contact)? clearContactPathCallback,
     Function(Contact, Uint8List, int)? setContactPathCallback,
-    Function(int pathLength, int messageBytes)? calculateTimeoutCallback,
+    Function(int pathLength, int messageBytes, {String? contactKey})?
+    calculateTimeoutCallback,
     Uint8List? Function()? getSelfPublicKeyCallback,
     String Function(Contact, String)? prepareContactOutboundTextCallback,
     AppSettingsService? appSettingsService,
     AppDebugLogService? debugLogService,
     Function(String, PathSelection, bool, int?)? recordPathResultCallback,
+    Function(
+      String contactKey,
+      int pathLength,
+      int messageBytes,
+      int tripTimeMs,
+    )?
+    onDeliveryObservedCallback,
   }) {
     _sendMessageCallback = sendMessageCallback;
     _addMessageCallback = addMessageCallback;
@@ -85,6 +100,7 @@ class MessageRetryService extends ChangeNotifier {
     _appSettingsService = appSettingsService;
     _debugLogService = debugLogService;
     _recordPathResultCallback = recordPathResultCallback;
+    _onDeliveryObservedCallback = onDeliveryObservedCallback;
   }
 
   /// Compute expected ACK hash using same algorithm as firmware:
@@ -156,7 +172,49 @@ class MessageRetryService extends ChangeNotifier {
       _addMessageCallback!(contact.publicKeyHex, message);
     }
 
-    await _attemptSend(messageId);
+    // Queue per contact — only one message in-flight at a time to avoid
+    // overflowing the firmware's 8-entry expected_ack_table.
+    final contactKey = contact.publicKeyHex;
+    _sendQueue[contactKey] ??= [];
+    _sendQueue[contactKey]!.add(messageId);
+
+    if (!_activeMessages.any(
+      (id) => _pendingContacts[id]?.publicKeyHex == contactKey,
+    )) {
+      _sendNextForContact(contactKey);
+    }
+  }
+
+  void _sendNextForContact(String contactKey) {
+    final queue = _sendQueue[contactKey];
+    if (queue == null) return;
+
+    // Drain stale entries iteratively instead of recursing.
+    while (queue.isNotEmpty) {
+      final messageId = queue.removeAt(0);
+      if (_pendingMessages.containsKey(messageId)) {
+        _activeMessages.add(messageId);
+        _attemptSend(messageId).catchError((e) {
+          debugPrint('_attemptSend threw for $messageId: $e');
+          final msg = _pendingMessages[messageId];
+          if (msg != null) {
+            final failed = msg.copyWith(status: MessageStatus.failed);
+            _pendingMessages[messageId] = failed;
+            _updateMessageCallback?.call(failed);
+          }
+          _onMessageResolved(messageId, contactKey);
+        });
+        return;
+      }
+      // Message was cancelled/cleaned up while queued — try next
+    }
+  }
+
+  void _onMessageResolved(String messageId, String contactKey) {
+    if (_resolvedMessages.contains(messageId)) return;
+    _resolvedMessages.add(messageId);
+    _activeMessages.remove(messageId);
+    _sendNextForContact(contactKey);
   }
 
   Future<void> _attemptSend(String messageId) async {
@@ -169,13 +227,11 @@ class MessageRetryService extends ChangeNotifier {
     // Use the path that was captured when the message was first sent
     if (_setContactPathCallback != null && _clearContactPathCallback != null) {
       if (message.pathLength != null && message.pathLength! < 0) {
-        // Flood mode - clear the path
         debugPrint(
           'Setting flood mode for retry attempt ${message.retryCount}',
         );
-        _clearContactPathCallback!(contact);
+        await _clearContactPathCallback!(contact);
       } else if (message.pathLength != null && message.pathLength! >= 0) {
-        // Specific path (including direct neighbor with pathLength=0)
         final pathStr = message.pathBytes.isEmpty
             ? 'direct'
             : message.pathBytes
@@ -192,6 +248,24 @@ class MessageRetryService extends ChangeNotifier {
       }
     }
 
+    // Re-validate after async gap — a timer or ACK could have resolved/retried
+    // this message while we were awaiting the path callback.
+    final currentMessage = _pendingMessages[messageId];
+    if (currentMessage == null || _resolvedMessages.contains(messageId)) {
+      debugPrint(
+        '_attemptSend: message $messageId resolved during path sync, aborting',
+      );
+      return;
+    }
+    // If the message was retried by a timer during our await, the retryCount
+    // will have advanced. Only proceed if it still matches the attempt we started.
+    if (currentMessage.retryCount != message.retryCount) {
+      debugPrint(
+        '_attemptSend: message $messageId retryCount changed during path sync, aborting',
+      );
+      return;
+    }
+
     final attempt = message.retryCount.clamp(0, 3);
     final timestampSeconds = message.timestamp.millisecondsSinceEpoch ~/ 1000;
 
@@ -231,6 +305,15 @@ class MessageRetryService extends ChangeNotifier {
 
     if (_sendMessageCallback != null) {
       _sendMessageCallback!(contact, message.text, attempt, timestampSeconds);
+    } else {
+      // No send callback — message would be stuck forever. Fail it immediately.
+      debugPrint(
+        '_attemptSend: no sendMessageCallback, failing message $messageId',
+      );
+      final failedMessage = message.copyWith(status: MessageStatus.failed);
+      _pendingMessages[messageId] = failedMessage;
+      _updateMessageCallback?.call(failedMessage);
+      _onMessageResolved(messageId, contact.publicKeyHex);
     }
   }
 
@@ -281,6 +364,7 @@ class MessageRetryService extends ChangeNotifier {
     }
 
     // FALLBACK: Old queue-based matching (for messages sent before hash computation was added)
+    // Only match within a single contact's queue to avoid cross-contact mismatches.
     if (messageId == null && allowQueueFallback) {
       _debugLogService?.warn(
         'RESP_CODE_SENT: ACK hash $ackHashHex not found in hash table, falling back to queue',
@@ -290,13 +374,16 @@ class MessageRetryService extends ChangeNotifier {
         'Hash-based match failed for $ackHashHex, falling back to queue-based matching',
       );
 
-      for (var entry in _pendingMessageQueuePerContact.entries) {
+      // Search all contact queues so concurrent chats don't miss matches.
+      final queuesToSearch = _pendingMessageQueuePerContact;
+
+      for (var entry in queuesToSearch.entries) {
         final contactKey = entry.key;
         final queue = entry.value;
 
-        if (queue.isNotEmpty) {
+        // Drain stale entries until we find a valid one or exhaust the queue.
+        while (queue.isNotEmpty) {
           final candidateMessageId = queue.removeAt(0);
-
           if (_pendingMessages.containsKey(candidateMessageId)) {
             messageId = candidateMessageId;
             contact = _pendingContacts[candidateMessageId];
@@ -304,21 +391,10 @@ class MessageRetryService extends ChangeNotifier {
               'Queue-based match (fallback): $ackHashHex → message $messageId for $contactKey',
             );
             break;
-          } else {
-            debugPrint('Dequeued stale message $candidateMessageId - skipping');
-            if (queue.isNotEmpty) {
-              final nextMessageId = queue.removeAt(0);
-              if (_pendingMessages.containsKey(nextMessageId)) {
-                messageId = nextMessageId;
-                contact = _pendingContacts[nextMessageId];
-                debugPrint(
-                  'Queue-based match (fallback): $ackHashHex → message $messageId',
-                );
-                break;
-              }
-            }
           }
+          debugPrint('Dequeued stale message $candidateMessageId - skipping');
         }
+        if (messageId != null) break;
       }
     }
 
@@ -357,25 +433,33 @@ class MessageRetryService extends ChangeNotifier {
       );
     }
 
-    // Use device-provided timeout, or calculate from radio settings if timeout is 0 or invalid
+    // Calculate timeout: prefer ML prediction, then device-provided, then physics fallback
+    int pathLengthValue;
+    if (selection != null) {
+      pathLengthValue = selection.useFlood ? -1 : selection.hopCount;
+      if (pathLengthValue < 0) pathLengthValue = contact.pathLength;
+    } else if (message.pathLength != null) {
+      pathLengthValue = message.pathLength!;
+    } else {
+      pathLengthValue = contact.pathLength;
+    }
+
     int actualTimeout = timeoutMs;
-    if (timeoutMs <= 0 && _calculateTimeoutCallback != null) {
+    if (_calculateTimeoutCallback != null) {
-      int pathLengthValue;
+      final calculated = _calculateTimeoutCallback!(
-      if (selection != null) {
-        pathLengthValue = selection.useFlood ? -1 : selection.hopCount;
-        if (pathLengthValue < 0) pathLengthValue = contact.pathLength;
-      } else if (message.pathLength != null) {
-        pathLengthValue = message.pathLength!;
-      } else {
-        pathLengthValue = contact.pathLength;
-      }
-      actualTimeout = _calculateTimeoutCallback!(
         pathLengthValue,
         message.text.length,
+        contactKey: contact.publicKeyHex,
       );
-      debugPrint(
+      // calculateTimeout tries ML first, falls back to physics.
-        'Using calculated timeout: ${actualTimeout}ms for path length $pathLengthValue',
+      // Use calculated value if device didn't provide one, or if ML
-      );
+      // produced a tighter prediction than the device's estimate.
+      if (timeoutMs <= 0 || calculated < timeoutMs) {
+        actualTimeout = calculated;
+        debugPrint(
+          'Using calculated timeout: ${actualTimeout}ms for path length $pathLengthValue',
+        );
+      }
     }
 
     final updatedMessage = message.copyWith(
@@ -463,22 +547,7 @@ class MessageRetryService extends ChangeNotifier {
     } else {
       // Max retries reached - mark as failed
       final failedMessage = message.copyWith(status: MessageStatus.failed);
-
+      _pendingMessages[messageId] = failedMessage;
-      // Move ACK hashes to history before removing
-      _moveAckHashesToHistory(messageId);
-
-      _pendingMessages.remove(messageId);
-      _pendingContacts.remove(messageId);
-      _pendingPathSelections.remove(messageId);
-      _timeoutTimers[messageId]?.cancel();
-      _timeoutTimers.remove(messageId);
-
-      // Clean up the queue entry for this contact
-      _pendingMessageQueuePerContact[contact.publicKeyHex]?.remove(messageId);
-      if (_pendingMessageQueuePerContact[contact.publicKeyHex]?.isEmpty ??
-          false) {
-        _pendingMessageQueuePerContact.remove(contact.publicKeyHex);
-      }
 
       // Check if we should clear the path on max retry
       if (_appSettingsService?.settings.clearPathOnMaxRetry == true &&
@@ -499,6 +568,30 @@ class MessageRetryService extends ChangeNotifier {
       }
 
       notifyListeners();
+
+      // Message is done retrying — send next queued message for this contact
+      _onMessageResolved(messageId, contact.publicKeyHex);
+
+      // Keep message in pending maps for 30s grace period so late ACKs
+      // can still match and update the message to delivered.
+      _timeoutTimers[messageId] = Timer(const Duration(seconds: 30), () {
+        _moveAckHashesToHistory(messageId);
+        // Clean up ALL hash mappings for this message
+        _ackHashToMessageId.removeWhere(
+          (_, mapping) => mapping.messageId == messageId,
+        );
+        _expectedHashToMessageId.removeWhere((_, msgId) => msgId == messageId);
+        _pendingMessages.remove(messageId);
+        _pendingContacts.remove(messageId);
+        _pendingPathSelections.remove(messageId);
+        _timeoutTimers.remove(messageId);
+        _resolvedMessages.remove(messageId);
+        final contactKey = contact.publicKeyHex;
+        _pendingMessageQueuePerContact[contactKey]?.remove(messageId);
+        if (_pendingMessageQueuePerContact[contactKey]?.isEmpty ?? false) {
+          _pendingMessageQueuePerContact.remove(contactKey);
+        }
+      });
     }
   }
 
@@ -594,7 +687,15 @@ class MessageRetryService extends ChangeNotifier {
     }
 
     if (matchedMessageId != null) {
-      final message = _pendingMessages[matchedMessageId]!;
+      final message = _pendingMessages[matchedMessageId];
+      if (message == null) {
+        // Message was already cleaned up (e.g. grace period expired)
+        _ackHashToMessageId.remove(ackHashHex);
+        debugPrint(
+          'ACK matched $matchedMessageId but message already cleaned up',
+        );
+        return;
+      }
       final contact = _pendingContacts[matchedMessageId];
       final selection = _pendingPathSelections[matchedMessageId];
 
@@ -616,12 +717,21 @@ class MessageRetryService extends ChangeNotifier {
         tripTimeMs: tripTimeMs,
       );
 
+      // Clean up ALL hash mappings for this message (from all retry attempts)
+      _ackHashToMessageId.removeWhere(
+        (_, mapping) => mapping.messageId == matchedMessageId,
+      );
+      _expectedHashToMessageId.removeWhere(
+        (_, msgId) => msgId == matchedMessageId,
+      );
+
       // Move ACK hashes to history before removing
       _moveAckHashesToHistory(matchedMessageId);
 
       _pendingMessages.remove(matchedMessageId);
       _pendingContacts.remove(matchedMessageId);
       _pendingPathSelections.remove(matchedMessageId);
+      _resolvedMessages.remove(matchedMessageId);
 
       // Clean up the queue entry for this contact (remove any remaining references to this message)
       if (contact != null) {
@@ -646,6 +756,17 @@ class MessageRetryService extends ChangeNotifier {
           true,
           tripTimeMs,
         );
+        if (_onDeliveryObservedCallback != null &&
+            tripTimeMs > 0 &&
+            message.pathLength != null) {
+          _onDeliveryObservedCallback!(
+            contact.publicKeyHex,
+            message.pathLength!,
+            message.text.length,
+            tripTimeMs,
+          );
+        }
+        _onMessageResolved(matchedMessageId, contact.publicKeyHex);
       }
 
       notifyListeners();
@@ -783,6 +904,9 @@ class MessageRetryService extends ChangeNotifier {
     _ackHistory.clear();
     _ackHashToMessageId.clear();
     _pendingMessageQueuePerContact.clear();
+    _sendQueue.clear();
+    _activeMessages.clear();
+    _resolvedMessages.clear();
     super.dispose();
   }
 }

lib/services/notification_service.dart

@@ -232,7 +232,9 @@ class NotificationService {
 
     try {
       await _notifications.show(
-        id: contactId?.hashCode ?? DateTime.now().millisecondsSinceEpoch,
+        id: contactId != null
+            ? 'advert:$contactId'.hashCode
+            : DateTime.now().millisecondsSinceEpoch,
         title: _l10n.notification_newTypeDiscovered(contactType),
         body: contactName,
         notificationDetails: notificationDetails,
@@ -331,6 +333,61 @@ class NotificationService {
     await _notifications.cancel(id: id);
   }
 
+  /// Cancel the notification for a specific contact and update the app badge.
+  Future<void> clearContactNotification(
+    String contactId,
+    int totalUnreadCount,
+  ) async {
+    if (!await _ensureInitialized()) return;
+    await _notifications.cancel(id: contactId.hashCode);
+    await _updateBadge(totalUnreadCount);
+  }
+
+  /// Cancel the notification for a specific channel and update the app badge.
+  Future<void> clearChannelNotification(
+    int channelIndex,
+    int totalUnreadCount,
+  ) async {
+    if (!await _ensureInitialized()) return;
+    await _notifications.cancel(id: channelIndex.hashCode);
+    await _updateBadge(totalUnreadCount);
+  }
+
+  /// Cancel advert notifications for the given contact public key hexes.
+  Future<void> clearAdvertNotifications(List<String> contactIds) async {
+    if (!await _ensureInitialized()) return;
+    for (final id in contactIds) {
+      await _notifications.cancel(id: 'advert:$id'.hashCode);
+    }
+  }
+
+  Future<void> _updateBadge(int count) async {
+    if (PlatformInfo.isIOS || PlatformInfo.isMacOS) {
+      // On Apple platforms, set the badge number directly via a silent update.
+      final darwinDetails = DarwinNotificationDetails(
+        presentAlert: false,
+        presentSound: false,
+        presentBadge: true,
+        badgeNumber: count,
+      );
+      final details = NotificationDetails(
+        iOS: darwinDetails,
+        macOS: darwinDetails,
+      );
+      // Use a fixed ID so each update replaces the previous one.
+      await _notifications.show(
+        id: 'badge_update'.hashCode,
+        title: null,
+        body: null,
+        notificationDetails: details,
+      );
+      // Immediately cancel the silent notification so it doesn't appear in tray.
+      await _notifications.cancel(id: 'badge_update'.hashCode);
+    }
+    // On Android, badge count is derived from active notifications,
+    // so cancelling the specific notification above is sufficient.
+  }
+
   // ─────────────────────────────────────────────────────────────────
   // Public notification methods (rate limiting is enforced automatically)
   // ─────────────────────────────────────────────────────────────────

lib/services/storage_service.dart

@@ -1,4 +1,5 @@
 import 'dart:convert';
+import '../models/delivery_observation.dart';
 import '../models/path_history.dart';
 import '../storage/prefs_manager.dart';
 
@@ -6,6 +7,7 @@ class StorageService {
   static const String _pathHistoryPrefix = 'path_history_';
   static const String _pendingMessagesKey = 'pending_messages';
   static const String _repeaterPasswordsKey = 'repeater_passwords';
+  static const String _deliveryObservationsKey = 'delivery_observations';
 
   Future<void> savePathHistory(
     String contactPubKeyHex,
@@ -122,4 +124,33 @@ class StorageService {
     final prefs = PrefsManager.instance;
     await prefs.remove(_repeaterPasswordsKey);
   }
+
+  Future<void> saveDeliveryObservations(
+    List<DeliveryObservation> observations,
+  ) async {
+    final prefs = PrefsManager.instance;
+    final jsonStr = jsonEncode(observations.map((o) => o.toJson()).toList());
+    await prefs.setString(_deliveryObservationsKey, jsonStr);
+  }
+
+  Future<List<DeliveryObservation>> loadDeliveryObservations() async {
+    final prefs = PrefsManager.instance;
+    final jsonStr = prefs.getString(_deliveryObservationsKey);
+
+    if (jsonStr == null) return [];
+
+    try {
+      final list = jsonDecode(jsonStr) as List;
+      return list
+          .map((e) => DeliveryObservation.fromJson(e as Map<String, dynamic>))
+          .toList();
+    } catch (e) {
+      return [];
+    }
+  }
+
+  Future<void> clearDeliveryObservations() async {
+    final prefs = PrefsManager.instance;
+    await prefs.remove(_deliveryObservationsKey);
+  }
 }

lib/services/timeout_prediction_service.dart

@@ -0,0 +1,229 @@
+import 'dart:async';
+import 'package:flutter/foundation.dart';
+import 'package:ml_algo/ml_algo.dart';
+import 'package:ml_dataframe/ml_dataframe.dart';
+import '../models/delivery_observation.dart';
+import 'storage_service.dart';
+
+class _ContactStats {
+  int count = 0;
+  double _sum = 0;
+
+  void add(double ms) {
+    count++;
+    _sum += ms;
+  }
+
+  double get mean => _sum / count;
+}
+
+class TimeoutPredictionService extends ChangeNotifier {
+  final StorageService? _storage;
+
+  static const int minObservations = 10;
+  static const int maxObservations = 100;
+  static const int _retrainInterval = 5;
+  // 1.5x multiplier on raw prediction to account for variance in delivery
+  // times — tight enough to improve on worst-case physics, loose enough
+  // to avoid premature timeouts from model noise.
+  static const double _safetyMargin = 1.5;
+  static const int _minContactObservations = 10;
+
+  List<DeliveryObservation> _observations = [];
+  LinearRegressor? _model;
+  List<String> _activeFeatures = [];
+  int _observationsSinceLastTrain = 0;
+  final Map<String, _ContactStats> _contactStats = {};
+  Timer? _persistTimer;
+
+  TimeoutPredictionService(StorageService storage) : _storage = storage;
+  TimeoutPredictionService.noStorage() : _storage = null;
+
+  int get observationCount => _observations.length;
+  bool get hasModel => _model != null;
+
+  Future<void> initialize() async {
+    _observations = await _storage?.loadDeliveryObservations() ?? [];
+    _rebuildContactStats();
+
+    if (_observations.length >= minObservations) {
+      _trainModel();
+    }
+
+    debugPrint(
+      'TimeoutPrediction: initialized with ${_observations.length} observations, '
+      'model=${_model != null ? "ready" : "waiting for data"}',
+    );
+  }
+
+  void recordObservation({
+    required String contactKey,
+    required int pathLength,
+    required int messageBytes,
+    required int tripTimeMs,
+    int secondsSinceLastRx = 0,
+  }) {
+    final observation = DeliveryObservation(
+      contactKey: contactKey,
+      pathLength: pathLength,
+      messageBytes: messageBytes,
+      secondsSinceLastRx: secondsSinceLastRx,
+      isFlood: pathLength < 0,
+      deliveryMs: tripTimeMs,
+      timestamp: DateTime.now(),
+    );
+
+    _observations.add(observation);
+    if (_observations.length > maxObservations) {
+      _observations.removeAt(0);
+    }
+
+    _contactStats.putIfAbsent(contactKey, () => _ContactStats());
+    _contactStats[contactKey]!.add(tripTimeMs.toDouble());
+
+    _observationsSinceLastTrain++;
+    if (_observationsSinceLastTrain >= _retrainInterval &&
+        _observations.length >= minObservations) {
+      _trainModel();
+    }
+
+    _persistTimer?.cancel();
+    _persistTimer = Timer(const Duration(seconds: 2), () {
+      _storage?.saveDeliveryObservations(_observations);
+    });
+    debugPrint(
+      'TimeoutPrediction: recorded ${tripTimeMs}ms for $pathLength hops '
+      '(${_observations.length} total)',
+    );
+  }
+
+  int? predictTimeout({
+    String? contactKey,
+    required int pathLength,
+    required int messageBytes,
+    int secondsSinceLastRx = 0,
+  }) {
+    if (_model == null) return null;
+
+    try {
+      if (_activeFeatures.isEmpty) return null;
+
+      final allFeatures = {
+        'pathLength': pathLength.toDouble(),
+        'messageBytes': messageBytes.toDouble(),
+        'secSinceRx': secondsSinceLastRx.toDouble(),
+        'isFlood': pathLength < 0 ? 1.0 : 0.0,
+      };
+      final row = _activeFeatures.map((f) => allFeatures[f]!).toList();
+
+      final features = DataFrame(
+        [row],
+        headerExists: false,
+        header: _activeFeatures,
+      );
+
+      final prediction = _model!.predict(features);
+      final rawValue = prediction.rows.first.first;
+      var predictedMs = (rawValue is double)
+          ? rawValue
+          : (rawValue as num).toDouble();
+
+      debugPrint(
+        'TimeoutPrediction: raw prediction=$predictedMs for '
+        'pathLength=$pathLength, messageBytes=$messageBytes, '
+        'features=$_activeFeatures',
+      );
+
+      // Sanity check: if prediction is negative or zero, fall back
+      if (predictedMs <= 0) return null;
+
+      // Blend with per-contact mean if enough data
+      if (contactKey != null) {
+        final stats = _contactStats[contactKey];
+        if (stats != null && stats.count >= _minContactObservations) {
+          predictedMs = 0.5 * predictedMs + 0.5 * stats.mean;
+        }
+      }
+
+      // Connector clamps this between physics min/max bounds
+      final timeout = (predictedMs * _safetyMargin).ceil();
+      debugPrint(
+        'TimeoutPrediction: ML timeout ${timeout}ms '
+        '(raw: ${predictedMs.round()}ms, contact: $contactKey)',
+      );
+      return timeout;
+    } catch (e) {
+      debugPrint('TimeoutPrediction: prediction failed: $e');
+      return null;
+    }
+  }
+
+  void _trainModel() {
+    try {
+      // Build feature columns, then exclude any with zero variance
+      // (ml_algo's OLS produces all-zero coefficients for singular matrices)
+      final allNames = ['pathLength', 'messageBytes', 'secSinceRx', 'isFlood'];
+      final allExtractors = <double Function(DeliveryObservation)>[
+        (o) => o.pathLength.toDouble(),
+        (o) => o.messageBytes.toDouble(),
+        (o) => o.secondsSinceLastRx.toDouble(),
+        (o) => o.isFlood ? 1.0 : 0.0,
+      ];
+
+      _activeFeatures = [];
+      for (var i = 0; i < allNames.length; i++) {
+        final values = _observations.map(allExtractors[i]).toSet();
+        if (values.length > 1) _activeFeatures.add(allNames[i]);
+      }
+
+      if (_activeFeatures.isEmpty) {
+        debugPrint(
+          'TimeoutPrediction: no features with variance, skipping training',
+        );
+        return;
+      }
+
+      final header = [..._activeFeatures, 'deliveryMs'];
+      final rows = _observations.map((o) {
+        final row = <double>[];
+        for (var i = 0; i < allNames.length; i++) {
+          if (_activeFeatures.contains(allNames[i])) {
+            row.add(allExtractors[i](o));
+          }
+        }
+        row.add(o.deliveryMs.toDouble());
+        return row;
+      });
+
+      final data = DataFrame([header, ...rows], headerExists: true);
+
+      _model = LinearRegressor(data, 'deliveryMs');
+      _observationsSinceLastTrain = 0;
+
+      // Log training summary with sample predictions
+      final avgMs =
+          _observations.map((o) => o.deliveryMs).reduce((a, b) => a + b) /
+          _observations.length;
+      debugPrint(
+        'TimeoutPrediction: trained on ${_observations.length} observations '
+        '(avg: ${avgMs.round()}ms, features: $_activeFeatures)',
+      );
+    } catch (e) {
+      debugPrint('TimeoutPrediction: training failed: $e');
+    }
+  }
+
+  @override
+  void dispose() {
+    _persistTimer?.cancel();
+    super.dispose();
+  }
+
+  void _rebuildContactStats() {
+    _contactStats.clear();
+    for (final obs in _observations) {
+      _contactStats.putIfAbsent(obs.contactKey, () => _ContactStats());
+      _contactStats[obs.contactKey]!.add(obs.deliveryMs.toDouble());
+    }
+  }
+}

macos/Flutter/GeneratedPluginRegistrant.swift

@@ -9,7 +9,6 @@ import flutter_blue_plus_darwin
 import flutter_local_notifications
 import mobile_scanner
 import package_info_plus
-import path_provider_foundation
 import share_plus
 import shared_preferences_foundation
 import sqflite_darwin
@@ -21,7 +20,6 @@ func RegisterGeneratedPlugins(registry: FlutterPluginRegistry) {
   FlutterLocalNotificationsPlugin.register(with: registry.registrar(forPlugin: "FlutterLocalNotificationsPlugin"))
   MobileScannerPlugin.register(with: registry.registrar(forPlugin: "MobileScannerPlugin"))
   FPPPackageInfoPlusPlugin.register(with: registry.registrar(forPlugin: "FPPPackageInfoPlusPlugin"))
-  PathProviderPlugin.register(with: registry.registrar(forPlugin: "PathProviderPlugin"))
   SharePlusMacosPlugin.register(with: registry.registrar(forPlugin: "SharePlusMacosPlugin"))
   SharedPreferencesPlugin.register(with: registry.registrar(forPlugin: "SharedPreferencesPlugin"))
   SqflitePlugin.register(with: registry.registrar(forPlugin: "SqflitePlugin"))

pubspec.yaml

@@ -69,6 +69,8 @@ dependencies:
   material_symbols_icons: ^4.2906.0
   web: ^1.1.1
   flutter_svg: ^2.0.10+1
+  ml_algo: ^16.0.0
+  ml_dataframe: ^1.0.0
 
 dev_dependencies:
   flutter_test:

test/services/ml_algo_sanity_test.dart

@@ -0,0 +1,156 @@
+import 'package:flutter/foundation.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:ml_algo/ml_algo.dart';
+import 'package:ml_dataframe/ml_dataframe.dart';
+
+void main() {
+  test('LinearRegressor basic sanity check', () {
+    // Simple: y = 2x + 100
+    final data = DataFrame(
+      [
+        [1.0, 102.0],
+        [2.0, 104.0],
+        [3.0, 106.0],
+        [4.0, 108.0],
+        [5.0, 110.0],
+        [10.0, 120.0],
+        [20.0, 140.0],
+        [50.0, 200.0],
+        [0.0, 100.0],
+        [100.0, 300.0],
+      ],
+      headerExists: false,
+      header: ['x', 'y'],
+    );
+
+    debugPrint('Training data columns: ${data.header}');
+    debugPrint('Training data rows: ${data.rows.length}');
+
+    final model = LinearRegressor(data, 'y');
+
+    final testDf = DataFrame(
+      [
+        [25.0],
+      ],
+      headerExists: false,
+      header: ['x'],
+    );
+
+    final prediction = model.predict(testDf);
+    final value = prediction.rows.first.first;
+    debugPrint('Predict x=25 → y=$value (expected ~150)');
+    expect((value as num).toDouble(), closeTo(150, 5));
+  });
+
+  test('LinearRegressor multi-feature with constant column produces zeros', () {
+    // isFlood=0 for all rows → zero-variance column → singular matrix
+    final data = DataFrame(
+      [
+        [0.0, 50.0, 14.0, 0.0, 1900.0],
+        [0.0, 80.0, 14.0, 0.0, 2200.0],
+        [2.0, 50.0, 14.0, 0.0, 5000.0],
+        [4.0, 50.0, 14.0, 0.0, 9500.0],
+      ],
+      headerExists: false,
+      header: [
+        'pathLength',
+        'messageBytes',
+        'hourOfDay',
+        'isFlood',
+        'deliveryMs',
+      ],
+    );
+
+    final model = LinearRegressor(data, 'deliveryMs');
+    final testDf = DataFrame(
+      [
+        [2.0, 50.0, 14.0, 0.0],
+      ],
+      headerExists: false,
+      header: ['pathLength', 'messageBytes', 'hourOfDay', 'isFlood'],
+    );
+    final pred = model.predict(testDf).rows.first.first;
+    debugPrint(
+      'With constant isFlood column: hops=2 → ${(pred as num).round()}ms (likely 0)',
+    );
+  });
+
+  test('LinearRegressor 2-feature works correctly', () {
+    // Just pathLength + messageBytes → deliveryMs
+    final data = DataFrame(
+      [
+        [0.0, 50.0, 1900.0],
+        [0.0, 80.0, 2200.0],
+        [2.0, 50.0, 5000.0],
+        [2.0, 80.0, 5500.0],
+        [4.0, 50.0, 9500.0],
+        [4.0, 80.0, 10000.0],
+        [0.0, 30.0, 1800.0],
+        [2.0, 30.0, 4800.0],
+        [4.0, 30.0, 9000.0],
+        [0.0, 60.0, 2000.0],
+      ],
+      headerExists: false,
+      header: ['pathLength', 'messageBytes', 'deliveryMs'],
+    );
+
+    final model = LinearRegressor(data, 'deliveryMs');
+
+    for (final hops in [0.0, 2.0, 4.0]) {
+      final testDf = DataFrame(
+        [
+          [hops, 50.0],
+        ],
+        headerExists: false,
+        header: ['pathLength', 'messageBytes'],
+      );
+      final pred = model.predict(testDf).rows.first.first;
+      debugPrint('2-feature: hops=$hops → ${(pred as num).round()}ms');
+    }
+  });
+
+  test('LinearRegressor multi-feature with variance in all columns', () {
+    // Mix flood and direct so isFlood has variance
+    final data = DataFrame(
+      [
+        [0.0, 50.0, 14.0, 0.0, 1900.0],
+        [0.0, 80.0, 10.0, 0.0, 2200.0],
+        [2.0, 50.0, 16.0, 0.0, 5000.0],
+        [2.0, 80.0, 20.0, 0.0, 5500.0],
+        [4.0, 50.0, 8.0, 0.0, 9500.0],
+        [4.0, 80.0, 12.0, 0.0, 10000.0],
+        [-1.0, 40.0, 14.0, 1.0, 5000.0],
+        [-1.0, 60.0, 18.0, 1.0, 6500.0],
+        [-1.0, 30.0, 10.0, 1.0, 4000.0],
+        [-1.0, 80.0, 22.0, 1.0, 7000.0],
+      ],
+      headerExists: false,
+      header: [
+        'pathLength',
+        'messageBytes',
+        'hourOfDay',
+        'isFlood',
+        'deliveryMs',
+      ],
+    );
+
+    final model = LinearRegressor(data, 'deliveryMs');
+
+    for (final tc in [
+      [0.0, 50.0, 14.0, 0.0],
+      [2.0, 50.0, 14.0, 0.0],
+      [4.0, 50.0, 14.0, 0.0],
+      [-1.0, 50.0, 14.0, 1.0],
+    ]) {
+      final testDf = DataFrame(
+        [tc],
+        headerExists: false,
+        header: ['pathLength', 'messageBytes', 'hourOfDay', 'isFlood'],
+      );
+      final pred = model.predict(testDf).rows.first.first;
+      debugPrint(
+        '4-feature: hops=${tc[0]} flood=${tc[3]} → ${(pred as num).round()}ms',
+      );
+    }
+  });
+}

test/services/timeout_prediction_service_test.dart

@@ -0,0 +1,164 @@
+import 'package:flutter/foundation.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:meshcore_open/models/delivery_observation.dart';
+import 'package:meshcore_open/services/timeout_prediction_service.dart';
+
+void main() {
+  late TimeoutPredictionService service;
+
+  setUp(() {
+    service = TimeoutPredictionService.noStorage();
+  });
+
+  test('trains on sample data and predicts sensible timeouts', () {
+    // Simulate realistic delivery data:
+    // Direct 0-hop messages: ~1500-2500ms
+    // 2-hop messages: ~4000-6000ms
+    // 4-hop messages: ~8000-12000ms
+    // Flood messages: ~3000-8000ms
+    final sampleData = [
+      // 0-hop direct
+      _obs(pathLength: 0, messageBytes: 20, deliveryMs: 1800),
+      _obs(pathLength: 0, messageBytes: 50, deliveryMs: 2100),
+      _obs(pathLength: 0, messageBytes: 80, deliveryMs: 2400),
+      _obs(pathLength: 0, messageBytes: 30, deliveryMs: 1925),
+      // 2-hop direct
+      _obs(pathLength: 2, messageBytes: 40, deliveryMs: 4500),
+      _obs(pathLength: 2, messageBytes: 60, deliveryMs: 5200),
+      _obs(pathLength: 2, messageBytes: 25, deliveryMs: 4100),
+      // 4-hop direct
+      _obs(pathLength: 4, messageBytes: 50, deliveryMs: 9800),
+      _obs(pathLength: 4, messageBytes: 30, deliveryMs: 8500),
+      _obs(pathLength: 4, messageBytes: 70, deliveryMs: 10570),
+      // Flood
+      _obs(pathLength: -1, messageBytes: 40, deliveryMs: 5000),
+      _obs(pathLength: -1, messageBytes: 60, deliveryMs: 6500),
+    ];
+
+    // Feed all observations
+    for (final obs in sampleData) {
+      service.recordObservation(
+        contactKey: obs.contactKey,
+        pathLength: obs.pathLength,
+        messageBytes: obs.messageBytes,
+        tripTimeMs: obs.deliveryMs,
+      );
+    }
+
+    expect(service.hasModel, isTrue);
+    expect(service.observationCount, equals(12));
+
+    // Predict for different scenarios
+    final direct0 = service.predictTimeout(pathLength: 0, messageBytes: 50);
+    final direct2 = service.predictTimeout(pathLength: 2, messageBytes: 50);
+    final direct4 = service.predictTimeout(pathLength: 4, messageBytes: 50);
+    final flood = service.predictTimeout(pathLength: -1, messageBytes: 50);
+
+    // All should return non-null (model is trained)
+    expect(direct0, isNotNull);
+    expect(direct2, isNotNull);
+    expect(direct4, isNotNull);
+    expect(flood, isNotNull);
+
+    // More hops should predict longer timeouts
+    expect(direct4!, greaterThan(direct2!));
+    expect(direct2, greaterThan(direct0!));
+
+    // All should be positive
+    expect(direct0, greaterThan(0));
+    expect(direct4, greaterThan(0));
+
+    // Print predictions for visibility
+    debugPrint('Predictions (with 1.5x safety margin):');
+    debugPrint('  0-hop direct: ${direct0}ms');
+    debugPrint('  2-hop direct: ${direct2}ms');
+    debugPrint('  4-hop direct: ${direct4}ms');
+    debugPrint('  flood:        ${flood}ms');
+  });
+
+  test('returns null before minimum observations', () {
+    for (var i = 0; i < TimeoutPredictionService.minObservations - 1; i++) {
+      service.recordObservation(
+        contactKey: 'abc',
+        pathLength: 0,
+        messageBytes: 50,
+        tripTimeMs: 2000,
+      );
+    }
+
+    expect(service.hasModel, isFalse);
+    expect(service.predictTimeout(pathLength: 0, messageBytes: 50), isNull);
+  });
+
+  test('caps observations at maxObservations', () {
+    for (var i = 0; i < TimeoutPredictionService.maxObservations + 20; i++) {
+      service.recordObservation(
+        contactKey: 'abc',
+        pathLength: 0,
+        messageBytes: 50,
+        tripTimeMs: 2000 + i,
+      );
+    }
+
+    expect(
+      service.observationCount,
+      equals(TimeoutPredictionService.maxObservations),
+    );
+  });
+
+  test('blends per-contact stats after enough observations', () {
+    // Train with mixed contacts and varied features:
+    // contactA is fast (0-hop), contactB is slow (2-hop)
+    for (var i = 0; i < 12; i++) {
+      service.recordObservation(
+        contactKey: 'contactA',
+        pathLength: 0,
+        messageBytes: 30 + i,
+        tripTimeMs: 1500,
+      );
+      service.recordObservation(
+        contactKey: 'contactB',
+        pathLength: 2,
+        messageBytes: 30 + i,
+        tripTimeMs: 8000,
+      );
+    }
+
+    final predA = service.predictTimeout(
+      contactKey: 'contactA',
+      pathLength: 0,
+      messageBytes: 50,
+    );
+    final predB = service.predictTimeout(
+      contactKey: 'contactB',
+      pathLength: 0,
+      messageBytes: 50,
+    );
+
+    expect(predA, isNotNull);
+    expect(predB, isNotNull);
+    // Contact B (slow) should have a higher predicted timeout than A (fast)
+    expect(predB!, greaterThan(predA!));
+
+    debugPrint('Per-contact blending:');
+    debugPrint('  contactA (fast): ${predA}ms');
+    debugPrint('  contactB (slow): ${predB}ms');
+  });
+}
+
+DeliveryObservation _obs({
+  required int pathLength,
+  required int messageBytes,
+  required int deliveryMs,
+  String contactKey = 'test_contact',
+}) {
+  return DeliveryObservation(
+    contactKey: contactKey,
+    pathLength: pathLength,
+    messageBytes: messageBytes,
+    secondsSinceLastRx: 5,
+    isFlood: pathLength < 0,
+    deliveryMs: deliveryMs,
+    timestamp: DateTime.now(),
+  );
+}