chore: update version to 7.0.0+8 in pubspec.yaml

Improvements to path tracing and location handling

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;
@@ -289,6 +294,10 @@ class MeshCoreConnector extends ChangeNotifier {
     );
   }
 
+  List<Contact> get allContacts => List.unmodifiable([
+    ..._contacts,
+    ..._discoveredContacts.where((c) => !c.isActive),
+  ]);
   List<Contact> get discoveredContacts {
     return List.unmodifiable(_discoveredContacts);
   }
@@ -668,6 +677,7 @@ class MeshCoreConnector extends ChangeNotifier {
     BleDebugLogService? bleDebugLogService,
     AppDebugLogService? appDebugLogService,
     BackgroundService? backgroundService,
+    TimeoutPredictionService? timeoutPredictionService,
   }) {
     _retryService = retryService;
     _pathHistoryService = pathHistoryService;
@@ -675,6 +685,7 @@ class MeshCoreConnector extends ChangeNotifier {
     _bleDebugLogService = bleDebugLogService;
     _appDebugLogService = appDebugLogService;
     _backgroundService = backgroundService;
+    _timeoutPredictionService = timeoutPredictionService;
     _usbManager.setDebugLogService(_appDebugLogService);
     _tcpConnector.setDebugLogService(_appDebugLogService);
 
@@ -689,13 +700,28 @@ class MeshCoreConnector extends ChangeNotifier {
       updateMessageCallback: _updateMessage,
       clearContactPathCallback: clearContactPath,
       setContactPathCallback: setContactPath,
-      calculateTimeoutCallback: (pathLength, messageBytes) =>
-          calculateTimeout(pathLength: pathLength, messageBytes: messageBytes),
+      calculateTimeoutCallback:
+          (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,
+            );
+          },
     );
   }
 
@@ -704,6 +730,9 @@ class MeshCoreConnector extends ChangeNotifier {
     _knownContactKeys
       ..clear()
       ..addAll(cached.map((c) => c.publicKeyHex));
+    _contacts
+      ..clear()
+      ..addAll(cached);
     for (final contact in cached) {
       _ensureContactSmazSettingLoaded(contact.publicKeyHex);
     }
@@ -1536,6 +1565,10 @@ class MeshCoreConnector extends ChangeNotifier {
 
     if (_activeTransport == MeshCoreTransportType.usb) {
       await _usbManager.write(data);
+      // Brief pause so the device firmware can process each frame before the
+      // next arrives. Without this, rapid-fire frames over USB can cause the
+      // device to miss responses (especially on reconnect).
+      await Future<void>.delayed(const Duration(milliseconds: 10));
     } else if (_activeTransport == MeshCoreTransportType.tcp) {
       await _tcpConnector.write(data);
     } else {
@@ -2498,6 +2531,7 @@ class MeshCoreConnector extends ChangeNotifier {
 
   void _handleFrame(List<int> data) {
     if (data.isEmpty) return;
+    _lastRxTime = DateTime.now();
 
     final frame = Uint8List.fromList(data);
     _receivedFramesController.add(frame);
@@ -2874,41 +2908,73 @@ class MeshCoreConnector extends ChangeNotifier {
     }
   }
 
-  /// 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}) {
-    // If we have radio settings, use them for accurate calculation
+  /// Estimate single-packet airtime in ms from radio settings, or a fallback.
+  int _estimateAirtimeMs(int messageBytes) {
     if (_currentFreqHz != null &&
         _currentBwHz != null &&
         _currentSf != null &&
         _currentCr != null) {
       final cr = _currentCr! <= 4 ? _currentCr! : _currentCr! - 4;
-      return calculateMessageTimeout(
-        freqHz: _currentFreqHz!,
-        bwHz: _currentBwHz!,
-        sf: _currentSf!,
-        cr: cr,
-        pathLength: pathLength,
-        messageBytes: messageBytes,
+      return calculateLoRaAirtime(
+        payloadBytes: messageBytes,
+        spreadingFactor: _currentSf!,
+        bandwidthHz: _currentBwHz!,
+        codingRate: cr,
+        lowDataRateOptimize: _currentSf! >= 11,
       );
     }
+    return 50; // fallback: ~SF7/BW125 for 100 bytes
+  }
 
-    // Fallback: Conservative estimates based on typical settings
-    // Assume SF7, BW125, which gives ~50ms airtime for 100 bytes
-    const estimatedAirtime = 50;
-
+  /// Physics-based worst-case timeout (ceiling).
+  int _physicsMaxTimeout(int pathLength, int airtime) {
     if (pathLength < 0) {
-      // Flood mode: Base delay + 16× airtime
-      return 500 + (16 * estimatedAirtime);
+      return 500 + (16 * airtime);
     } else {
-      // Direct path: Base delay + ((airtime×6 + 250ms)×(hops+1))
-      return 500 + ((estimatedAirtime * 6 + 250) * (pathLength + 1));
+      return 500 + ((airtime * 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) {
+      _handleDiscovery(contact, frame, noNotify: true, addActive: true);
+
       if (contact.type == advTypeRepeater) {
         _contactUnreadCount.remove(contact.publicKeyHex);
         _unreadStore.saveContactUnreadCount(
@@ -4717,6 +4783,12 @@ class MeshCoreConnector extends ChangeNotifier {
           (_autoAddRoomServers && type == advTypeRoom) ||
           (_autoAddSensors && type == advTypeSensor)) {
         _handleContactAdvert(newContact);
+        _handleDiscovery(
+          newContact,
+          rawPacket,
+          noNotify: true,
+          addActive: true,
+        );
       } else {
         _handleDiscovery(newContact, rawPacket);
       }
@@ -4741,8 +4813,20 @@ class MeshCoreConnector extends ChangeNotifier {
 
       // CRITICAL: Preserve user's path override when contact is refreshed from device
       _contacts[existingIndex] = existing.copyWith(
-        latitude: hasLocation ? latitude : existing.latitude,
-        longitude: hasLocation ? longitude : existing.longitude,
+        latitude:
+            hasLocation &&
+                latitude != null &&
+                latitude.abs() <= 90 &&
+                (latitude != 0 || longitude != 0)
+            ? latitude
+            : existing.latitude,
+        longitude:
+            hasLocation &&
+                longitude != null &&
+                longitude.abs() <= 180 &&
+                (latitude != 0 || longitude != 0)
+            ? longitude
+            : existing.longitude,
         name: hasName ? name : existing.name,
         path: Uint8List.fromList(path.reversed.toList()),
         pathLength: path.length,
@@ -4813,11 +4897,11 @@ class MeshCoreConnector extends ChangeNotifier {
     try {
       reader.skipBytes(1); // Skip the response code byte
       final flags = reader.readByte();
-      _autoAddUsers = flags & autoAddChatFlag != 0;
-      _autoAddRepeaters = flags & autoAddRepeaterFlag != 0;
-      _autoAddRoomServers = flags & autoAddRoomServerFlag != 0;
-      _autoAddSensors = flags & autoAddSensorFlag != 0;
-      _overwriteOldest = flags & autoAddOverwriteOldestFlag != 0;
+      _autoAddUsers = (flags & autoAddChatFlag) != 0;
+      _autoAddRepeaters = (flags & autoAddRepeaterFlag) != 0;
+      _autoAddRoomServers = (flags & autoAddRoomServerFlag) != 0;
+      _autoAddSensors = (flags & autoAddSensorFlag) != 0;
+      _overwriteOldest = (flags & autoAddOverwriteOldestFlag) != 0;
     } catch (e) {
       appLogger.error('Failed to parse auto-add config: $e', tag: 'Connector');
     }
@@ -4827,6 +4911,7 @@ class MeshCoreConnector extends ChangeNotifier {
     Contact contact,
     Uint8List rawPacket, {
     bool noNotify = false,
+    bool addActive = false,
   }) {
     appLogger.info('Discovered new contact: ${contact.name}', tag: 'Connector');
 
@@ -4847,7 +4932,7 @@ class MeshCoreConnector extends ChangeNotifier {
             longitude: contact.longitude,
             lastSeen: contact.lastSeen,
             flags: 0,
-            isActive: false,
+            isActive: addActive,
           );
       notifyListeners();
       unawaited(_persistDiscoveredContacts());
@@ -4865,7 +4950,7 @@ class MeshCoreConnector extends ChangeNotifier {
       longitude: contact.longitude,
       lastSeen: contact.lastSeen,
       lastMessageAt: contact.lastMessageAt,
-      isActive: false,
+      isActive: addActive,
       flags: 0,
     );
     _discoveredContacts.add(disContact);

lib/connector/meshcore_connector_usb.dart

@@ -64,6 +64,8 @@ class MeshCoreUsbManager {
 
   Future<void> write(Uint8List data) => _service.write(data);
 
+  Future<void> writeRaw(Uint8List data) => _service.writeRaw(data);
+
   // --- Label management ---
   void updateConnectedLabel(String selfName) {
     _service.updateConnectedLabel(selfName);

lib/l10n/app_bg.arb

@@ -285,6 +285,7 @@
   "contacts_newGroup": "Нова група",
   "contacts_groupName": "Група",
   "contacts_groupNameRequired": "Името на групата е задължително.",
+  "contacts_groupNameReserved": "Това име на група е запазено",
   "contacts_groupAlreadyExists": "Групата \"{name}\" вече съществува.",
   "@contacts_groupAlreadyExists": {
     "placeholders": {

lib/l10n/app_de.arb

@@ -285,6 +285,7 @@
   "contacts_newGroup": "Neue Gruppe",
   "contacts_groupName": "Gruppenname",
   "contacts_groupNameRequired": "Der Gruppennamen ist erforderlich.",
+  "contacts_groupNameReserved": "Dieser Gruppenname ist reserviert",
   "contacts_groupAlreadyExists": "Die Gruppe \"{name}\" existiert bereits.",
   "@contacts_groupAlreadyExists": {
     "placeholders": {

lib/l10n/app_en.arb

@@ -416,6 +416,7 @@
   "contacts_newGroup": "New Group",
   "contacts_groupName": "Group name",
   "contacts_groupNameRequired": "Group name is required",
+  "contacts_groupNameReserved": "This group name is reserved",
   "contacts_groupAlreadyExists": "Group \"{name}\" already exists",
   "@contacts_groupAlreadyExists": {
     "placeholders": {

lib/l10n/app_es.arb

@@ -285,6 +285,7 @@
   "contacts_newGroup": "Nuevo Grupo",
   "contacts_groupName": "Nombre del grupo",
   "contacts_groupNameRequired": "El nombre del grupo es obligatorio",
+  "contacts_groupNameReserved": "Este nombre de grupo está reservado",
   "contacts_groupAlreadyExists": "El grupo \"{name}\" ya existe",
   "@contacts_groupAlreadyExists": {
     "placeholders": {

lib/l10n/app_fr.arb

@@ -285,6 +285,7 @@
   "contacts_newGroup": "Nouveau Groupe",
   "contacts_groupName": "Nom du groupe",
   "contacts_groupNameRequired": "Le nom du groupe est obligatoire.",
+  "contacts_groupNameReserved": "Ce nom de groupe est réservé",
   "contacts_groupAlreadyExists": "Le groupe \"{name}\" existe déjà.",
   "@contacts_groupAlreadyExists": {
     "placeholders": {

lib/l10n/app_it.arb

@@ -285,6 +285,7 @@
   "contacts_newGroup": "Nuovo Gruppo",
   "contacts_groupName": "Nome gruppo",
   "contacts_groupNameRequired": "Il nome del gruppo è obbligatorio.",
+  "contacts_groupNameReserved": "Questo nome del gruppo è riservato",
   "contacts_groupAlreadyExists": "Il gruppo \"{name}\" esiste già.",
   "@contacts_groupAlreadyExists": {
     "placeholders": {

lib/l10n/app_localizations.dart

@@ -1714,6 +1714,12 @@ abstract class AppLocalizations {
   /// **'Group name is required'**
   String get contacts_groupNameRequired;
 
+  /// No description provided for @contacts_groupNameReserved.
+  ///
+  /// In en, this message translates to:
+  /// **'This group name is reserved'**
+  String get contacts_groupNameReserved;
+
   /// No description provided for @contacts_groupAlreadyExists.
   ///
   /// In en, this message translates to:

lib/l10n/app_localizations_bg.dart

@@ -902,6 +902,9 @@ class AppLocalizationsBg extends AppLocalizations {
   @override
   String get contacts_groupNameRequired => 'Името на групата е задължително.';
 
+  @override
+  String get contacts_groupNameReserved => 'Това име на група е запазено';
+
   @override
   String contacts_groupAlreadyExists(String name) {
     return 'Групата \"$name\" вече съществува.';

lib/l10n/app_localizations_de.dart

@@ -902,6 +902,9 @@ class AppLocalizationsDe extends AppLocalizations {
   @override
   String get contacts_groupNameRequired => 'Der Gruppennamen ist erforderlich.';
 
+  @override
+  String get contacts_groupNameReserved => 'Dieser Gruppenname ist reserviert';
+
   @override
   String contacts_groupAlreadyExists(String name) {
     return 'Die Gruppe \"$name\" existiert bereits.';

lib/l10n/app_localizations_en.dart

@@ -889,6 +889,9 @@ class AppLocalizationsEn extends AppLocalizations {
   @override
   String get contacts_groupNameRequired => 'Group name is required';
 
+  @override
+  String get contacts_groupNameReserved => 'This group name is reserved';
+
   @override
   String contacts_groupAlreadyExists(String name) {
     return 'Group \"$name\" already exists';

lib/l10n/app_localizations_es.dart

@@ -901,6 +901,10 @@ class AppLocalizationsEs extends AppLocalizations {
   @override
   String get contacts_groupNameRequired => 'El nombre del grupo es obligatorio';
 
+  @override
+  String get contacts_groupNameReserved =>
+      'Este nombre de grupo está reservado';
+
   @override
   String contacts_groupAlreadyExists(String name) {
     return 'El grupo \"$name\" ya existe';

lib/l10n/app_localizations_fr.dart

@@ -905,6 +905,9 @@ class AppLocalizationsFr extends AppLocalizations {
   @override
   String get contacts_groupNameRequired => 'Le nom du groupe est obligatoire.';
 
+  @override
+  String get contacts_groupNameReserved => 'Ce nom de groupe est réservé';
+
   @override
   String contacts_groupAlreadyExists(String name) {
     return 'Le groupe \"$name\" existe déjà.';

lib/l10n/app_localizations_it.dart

@@ -901,6 +901,9 @@ class AppLocalizationsIt extends AppLocalizations {
   @override
   String get contacts_groupNameRequired => 'Il nome del gruppo è obbligatorio.';
 
+  @override
+  String get contacts_groupNameReserved => 'Questo nome del gruppo è riservato';
+
   @override
   String contacts_groupAlreadyExists(String name) {
     return 'Il gruppo \"$name\" esiste già.';

lib/l10n/app_localizations_nl.dart

@@ -895,6 +895,9 @@ class AppLocalizationsNl extends AppLocalizations {
   @override
   String get contacts_groupNameRequired => 'De groepnaam is verplicht.';
 
+  @override
+  String get contacts_groupNameReserved => 'Deze groepsnaam is gereserveerd';
+
   @override
   String contacts_groupAlreadyExists(String name) {
     return 'De groep \"$name\" bestaat al.';

lib/l10n/app_localizations_pl.dart

@@ -904,6 +904,9 @@ class AppLocalizationsPl extends AppLocalizations {
   @override
   String get contacts_groupNameRequired => 'Nazwa grupy jest wymagana';
 
+  @override
+  String get contacts_groupNameReserved => 'Ta nazwa grupy jest zastrzeżona';
+
   @override
   String contacts_groupAlreadyExists(String name) {
     return 'Grupa \"$name\" już istnieje';

lib/l10n/app_localizations_pt.dart

@@ -903,6 +903,9 @@ class AppLocalizationsPt extends AppLocalizations {
   @override
   String get contacts_groupNameRequired => 'O nome do grupo é obrigatório.';
 
+  @override
+  String get contacts_groupNameReserved => 'Este nome de grupo está reservado';
+
   @override
   String contacts_groupAlreadyExists(String name) {
     return 'O grupo \"$name\" já existe';

lib/l10n/app_localizations_ru.dart

@@ -902,6 +902,9 @@ class AppLocalizationsRu extends AppLocalizations {
   @override
   String get contacts_groupNameRequired => 'Имя группы обязательно';
 
+  @override
+  String get contacts_groupNameReserved => 'Это имя группы зарезервировано';
+
   @override
   String contacts_groupAlreadyExists(String name) {
     return 'Группа \"$name\" уже существует';

lib/l10n/app_localizations_sk.dart

@@ -894,6 +894,9 @@ class AppLocalizationsSk extends AppLocalizations {
   @override
   String get contacts_groupNameRequired => 'Skupina musí mať názov.';
 
+  @override
+  String get contacts_groupNameReserved => 'Tento názov skupiny je rezervovaný';
+
   @override
   String contacts_groupAlreadyExists(String name) {
     return 'Skupina \"$name\" už existuje';

lib/l10n/app_localizations_sl.dart

@@ -892,6 +892,9 @@ class AppLocalizationsSl extends AppLocalizations {
   @override
   String get contacts_groupNameRequired => 'Ime skupine je obvezno.';
 
+  @override
+  String get contacts_groupNameReserved => 'To ime skupine je rezervirano';
+
   @override
   String contacts_groupAlreadyExists(String name) {
     return 'Skupina \"$name\" že obstaja';

lib/l10n/app_localizations_sv.dart

@@ -888,6 +888,9 @@ class AppLocalizationsSv extends AppLocalizations {
   @override
   String get contacts_groupNameRequired => 'Gruppnamnet är obligatoriskt';
 
+  @override
+  String get contacts_groupNameReserved => 'Detta gruppnamn är reserverat';
+
   @override
   String contacts_groupAlreadyExists(String name) {
     return 'Gruppen \"$name\" finns redan.';

lib/l10n/app_localizations_uk.dart

@@ -898,6 +898,9 @@ class AppLocalizationsUk extends AppLocalizations {
   @override
   String get contacts_groupNameRequired => 'Назва групи обов\'язкова.';
 
+  @override
+  String get contacts_groupNameReserved => 'Ця назва групи зарезервована';
+
   @override
   String contacts_groupAlreadyExists(String name) {
     return 'Група «$name» вже існує.';

lib/l10n/app_localizations_zh.dart

@@ -845,6 +845,9 @@ class AppLocalizationsZh extends AppLocalizations {
   @override
   String get contacts_groupNameRequired => '请输入群聊名称';
 
+  @override
+  String get contacts_groupNameReserved => '该群组名称已被保留';
+
   @override
   String contacts_groupAlreadyExists(String name) {
     return '名为 \"$name\" 的群聊已存在';

lib/l10n/app_nl.arb

@@ -285,6 +285,7 @@
   "contacts_newGroup": "Nieuwe Groep",
   "contacts_groupName": "Groepnaam",
   "contacts_groupNameRequired": "De groepnaam is verplicht.",
+  "contacts_groupNameReserved": "Deze groepsnaam is gereserveerd",
   "contacts_groupAlreadyExists": "De groep \"{name}\" bestaat al.",
   "@contacts_groupAlreadyExists": {
     "placeholders": {

lib/l10n/app_pl.arb

@@ -285,6 +285,7 @@
   "contacts_newGroup": "Nowa Grupa",
   "contacts_groupName": "Nazwa grupy",
   "contacts_groupNameRequired": "Nazwa grupy jest wymagana",
+  "contacts_groupNameReserved": "Ta nazwa grupy jest zastrzeżona",
   "contacts_groupAlreadyExists": "Grupa \"{name}\" już istnieje",
   "@contacts_groupAlreadyExists": {
     "placeholders": {

lib/l10n/app_pt.arb

@@ -285,6 +285,7 @@
   "contacts_newGroup": "Novo Grupo",
   "contacts_groupName": "Nome do grupo",
   "contacts_groupNameRequired": "O nome do grupo é obrigatório.",
+  "contacts_groupNameReserved": "Este nome de grupo está reservado",
   "contacts_groupAlreadyExists": "O grupo \"{name}\" já existe",
   "@contacts_groupAlreadyExists": {
     "placeholders": {

lib/l10n/app_ru.arb

@@ -212,6 +212,7 @@
   "contacts_newGroup": "Новая группа",
   "contacts_groupName": "Имя группы",
   "contacts_groupNameRequired": "Имя группы обязательно",
+  "contacts_groupNameReserved": "Это имя группы зарезервировано",
   "contacts_groupAlreadyExists": "Группа \"{name}\" уже существует",
   "contacts_filterContacts": "Фильтр контактов...",
   "contacts_noContactsMatchFilter": "Нет контактов, соответствующих фильтру",

lib/l10n/app_sk.arb

@@ -285,6 +285,7 @@
   "contacts_newGroup": "Nová skupina",
   "contacts_groupName": "Názov skupiny",
   "contacts_groupNameRequired": "Skupina musí mať názov.",
+  "contacts_groupNameReserved": "Tento názov skupiny je rezervovaný",
   "contacts_groupAlreadyExists": "Skupina \"{name}\" už existuje",
   "@contacts_groupAlreadyExists": {
     "placeholders": {

lib/l10n/app_sl.arb

@@ -285,6 +285,7 @@
   "contacts_newGroup": "Nova skupina",
   "contacts_groupName": "Ime skupine",
   "contacts_groupNameRequired": "Ime skupine je obvezno.",
+  "contacts_groupNameReserved": "To ime skupine je rezervirano",
   "contacts_groupAlreadyExists": "Skupina \"{name}\" že obstaja",
   "@contacts_groupAlreadyExists": {
     "placeholders": {

lib/l10n/app_sv.arb

@@ -285,6 +285,7 @@
   "contacts_newGroup": "Ny grupp",
   "contacts_groupName": "Gruppnamn",
   "contacts_groupNameRequired": "Gruppnamnet är obligatoriskt",
+  "contacts_groupNameReserved": "Detta gruppnamn är reserverat",
   "contacts_groupAlreadyExists": "Gruppen \"{name}\" finns redan.",
   "@contacts_groupAlreadyExists": {
     "placeholders": {

lib/l10n/app_uk.arb

@@ -286,6 +286,7 @@
   "contacts_newGroup": "Нова група",
   "contacts_groupName": "Назва групи",
   "contacts_groupNameRequired": "Назва групи обов'язкова.",
+  "contacts_groupNameReserved": "Ця назва групи зарезервована",
   "contacts_groupAlreadyExists": "Група «{name}» вже існує.",
   "@contacts_groupAlreadyExists": {
     "placeholders": {

lib/l10n/app_zh.arb

@@ -300,6 +300,7 @@
   "contacts_newGroup": "新建群聊",
   "contacts_groupName": "群聊名称",
   "contacts_groupNameRequired": "请输入群聊名称",
+  "contacts_groupNameReserved": "该群组名称已被保留",
   "contacts_groupAlreadyExists": "名为 \"{name}\" 的群聊已存在",
   "@contacts_groupAlreadyExists": {
     "placeholders": {

lib/main.dart

@@ -19,6 +19,8 @@ import 'services/app_debug_log_service.dart';
 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';
 
@@ -39,6 +41,8 @@ void main() async {
   final backgroundService = BackgroundService();
   final mapTileCacheService = MapTileCacheService();
   final chatTextScaleService = ChatTextScaleService();
+  final uiViewStateService = UiViewStateService();
+  final timeoutPredictionService = TimeoutPredictionService(storage);
 
   // Load settings
   await appSettingsService.loadSettings();
@@ -56,6 +60,8 @@ void main() async {
   _registerThirdPartyLicenses();
 
   await chatTextScaleService.initialize();
+  await uiViewStateService.initialize();
+  await timeoutPredictionService.initialize();
 
   // Wire up connector with services
   connector.initialize(
@@ -65,6 +71,7 @@ void main() async {
     bleDebugLogService: bleDebugLogService,
     appDebugLogService: appDebugLogService,
     backgroundService: backgroundService,
+    timeoutPredictionService: timeoutPredictionService,
   );
 
   await connector.loadContactCache();
@@ -86,6 +93,8 @@ void main() async {
       appDebugLogService: appDebugLogService,
       mapTileCacheService: mapTileCacheService,
       chatTextScaleService: chatTextScaleService,
+      uiViewStateService: uiViewStateService,
+      timeoutPredictionService: timeoutPredictionService,
     ),
   );
 }
@@ -121,6 +130,8 @@ class MeshCoreApp extends StatelessWidget {
   final AppDebugLogService appDebugLogService;
   final MapTileCacheService mapTileCacheService;
   final ChatTextScaleService chatTextScaleService;
+  final UiViewStateService uiViewStateService;
+  final TimeoutPredictionService timeoutPredictionService;
 
   const MeshCoreApp({
     super.key,
@@ -133,6 +144,8 @@ class MeshCoreApp extends StatelessWidget {
     required this.appDebugLogService,
     required this.mapTileCacheService,
     required this.chatTextScaleService,
+    required this.uiViewStateService,
+    required this.timeoutPredictionService,
   });
 
   @override
@@ -146,8 +159,10 @@ class MeshCoreApp extends StatelessWidget {
         ChangeNotifierProvider.value(value: bleDebugLogService),
         ChangeNotifierProvider.value(value: appDebugLogService),
         ChangeNotifierProvider.value(value: chatTextScaleService),
+        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/app_settings.dart

@@ -40,6 +40,8 @@ class AppSettings {
   final UnitSystem unitSystem;
   final Set<String> mutedChannels;
   final bool mapShowDiscoveryContacts;
+  final String tcpServerAddress;
+  final int tcpServerPort;
 
   AppSettings({
     this.clearPathOnMaxRetry = false,
@@ -68,6 +70,8 @@ class AppSettings {
     this.unitSystem = UnitSystem.metric,
     Set<String>? mutedChannels,
     this.mapShowDiscoveryContacts = true,
+    this.tcpServerAddress = '',
+    this.tcpServerPort = 0,
   }) : batteryChemistryByDeviceId = batteryChemistryByDeviceId ?? {},
        batteryChemistryByRepeaterId = batteryChemistryByRepeaterId ?? {},
        mutedChannels = mutedChannels ?? {};
@@ -100,6 +104,8 @@ class AppSettings {
       'unit_system': unitSystem.value,
       'muted_channels': mutedChannels.toList(),
       'map_show_discovery_contacts': mapShowDiscoveryContacts,
+      'tcp_server_address': tcpServerAddress,
+      'tcp_server_port': tcpServerPort,
     };
   }
 
@@ -157,6 +163,8 @@ class AppSettings {
           {},
       mapShowDiscoveryContacts:
           json['map_show_discovery_contacts'] as bool? ?? true,
+      tcpServerAddress: json['tcp_server_address'] as String? ?? '',
+      tcpServerPort: json['tcp_server_port'] as int? ?? 0,
     );
   }
 
@@ -187,6 +195,8 @@ class AppSettings {
     UnitSystem? unitSystem,
     Set<String>? mutedChannels,
     bool? mapShowDiscoveryContacts,
+    String? tcpServerAddress,
+    int? tcpServerPort,
   }) {
     return AppSettings(
       clearPathOnMaxRetry: clearPathOnMaxRetry ?? this.clearPathOnMaxRetry,
@@ -225,6 +235,8 @@ class AppSettings {
       mutedChannels: mutedChannels ?? this.mutedChannels,
       mapShowDiscoveryContacts:
           mapShowDiscoveryContacts ?? this.mapShowDiscoveryContacts,
+      tcpServerAddress: tcpServerAddress ?? this.tcpServerAddress,
+      tcpServerPort: tcpServerPort ?? this.tcpServerPort,
     );
   }
 }

lib/models/contact.dart

@@ -65,7 +65,17 @@ class Contact {
     return '$pathLength hops';
   }
 
-  bool get hasLocation => latitude != null && longitude != null;
+  bool get hasLocation {
+    const double epsilon = 1e-6;
+    final lat = latitude ?? 0.0;
+    final lon = longitude ?? 0.0;
+    return (lat.abs() > epsilon || lon.abs() > epsilon) &&
+        lat >= -90.0 &&
+        lat <= 90.0 &&
+        lon >= -180.0 &&
+        lon <= 180.0;
+  }
+
   bool get isFavorite => (flags & contactFlagFavorite) != 0;
 
   Contact copyWith({
@@ -108,7 +118,7 @@ class Contact {
   }
 
   String get pathIdList {
-    final pathBytes = _pathBytesForDisplay;
+    final pathBytes = pathBytesForDisplay;
     if (pathBytes.isEmpty) return '';
     final parts = <String>[];
     final groupSize = pathHashSize;
@@ -130,43 +140,7 @@ class Contact {
     return "<${publicKeyHex.substring(0, 8)}...${publicKeyHex.substring(publicKeyHex.length - 8)}>";
   }
 
-  Uint8List? get traceRouteBytes {
-    final pathBytes = _pathBytesForDisplay;
-    Uint8List? traceBytes;
-
-    if (pathBytes.isEmpty) {
-      traceBytes = Uint8List(1);
-      traceBytes[0] = publicKey[0];
-      return traceBytes;
-    }
-
-    if (type == advTypeRepeater || type == advTypeRoom) {
-      final len = (pathBytes.length + pathBytes.length + 1);
-      traceBytes = Uint8List(len);
-      traceBytes[pathBytes.length] = publicKey[0];
-      for (int i = 0; i < pathBytes.length; i++) {
-        traceBytes[i] = pathBytes[i];
-        if (i < pathBytes.length) {
-          traceBytes[len - 1 - i] = pathBytes[i];
-        }
-      }
-    } else {
-      if (pathBytes.length < 2) {
-        return pathBytes[0] == 0 ? null : pathBytes;
-      }
-      final len = (pathBytes.length + pathBytes.length - 1);
-      traceBytes = Uint8List(len);
-      for (int i = 0; i < pathBytes.length; i++) {
-        traceBytes[i] = pathBytes[i];
-        if (i < pathBytes.length - 1) {
-          traceBytes[len - 1 - i] = pathBytes[i];
-        }
-      }
-    }
-    return traceBytes;
-  }
-
-  Uint8List get _pathBytesForDisplay {
+  Uint8List get pathBytesForDisplay {
     if (pathOverride != null) {
       if (pathOverride! < 0) return Uint8List(0);
       return pathOverrideBytes ?? Uint8List(0);
@@ -197,6 +171,7 @@ class Contact {
       double? lat, lon;
       final latRaw = reader.readInt32LE();
       final lonRaw = reader.readInt32LE();
+
       if (latRaw != 0 || lonRaw != 0) {
         lat = latRaw / 1e6;
         lon = lonRaw / 1e6;

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/channel_message_path_screen.dart

@@ -40,10 +40,7 @@ class ChannelMessagePathScreen extends StatelessWidget {
         final primaryPath = !channelMessage && !message.isOutgoing
             ? Uint8List.fromList(primaryPathTmp.reversed.toList())
             : primaryPathTmp;
-        final contacts = <Contact>[
-          ...connector.contacts,
-          ...connector.discoveredContacts,
-        ];
+        final contacts = connector.allContacts;
         final hops = _buildPathHops(primaryPath, contacts, l10n);
         final hasHopDetails = primaryPath.isNotEmpty;
         final observedLabel = _formatObservedHops(
@@ -65,8 +62,9 @@ class ChannelMessagePathScreen extends StatelessWidget {
                     builder: (context) => PathTraceMapScreen(
                       title: context.l10n.contacts_repeaterPathTrace,
                       path: primaryPath,
-                      flipPathRound: true,
-                      reversePathRound: !message.isOutgoing && !channelMessage,
+                      flipPathAround: true,
+                      reversePathAround:
+                          !(!channelMessage && !message.isOutgoing),
                     ),
                   ),
                 ),
@@ -367,10 +365,7 @@ class _ChannelMessagePathMapScreenState
             : selectedPathTmp;
 
         final selectedIndex = _indexForPath(selectedPath, observedPaths);
-        final contacts = <Contact>[
-          ...connector.contacts,
-          ...connector.discoveredContacts,
-        ];
+        final contacts = connector.allContacts;
         final hops = _buildPathHops(selectedPath, contacts, context.l10n);
 
         final points = <LatLng>[];

lib/screens/channels_screen.dart

@@ -11,6 +11,7 @@ import 'package:uuid/uuid.dart';
 import '../connector/meshcore_connector.dart';
 import '../l10n/l10n.dart';
 import '../services/app_settings_service.dart';
+import '../services/ui_view_state_service.dart';
 import '../models/channel.dart';
 import '../models/community.dart';
 import '../storage/community_store.dart';
@@ -28,8 +29,6 @@ import 'contacts_screen.dart';
 import 'map_screen.dart';
 import 'settings_screen.dart';
 
-enum ChannelSortOption { manual, name, latestMessages, unread }
-
 class ChannelsScreen extends StatefulWidget {
   final bool hideBackButton;
 
@@ -43,9 +42,7 @@ class _ChannelsScreenState extends State<ChannelsScreen>
     with DisconnectNavigationMixin {
   final TextEditingController _searchController = TextEditingController();
   final CommunityStore _communityStore = CommunityStore();
-  String _searchQuery = '';
   Timer? _searchDebounce;
-  ChannelSortOption _sortOption = ChannelSortOption.manual;
   List<Community> _communities = [];
 
   // Cache of PSK hex -> Community for quick lookup
@@ -56,6 +53,9 @@ class _ChannelsScreenState extends State<ChannelsScreen>
   @override
   void initState() {
     super.initState();
+    _searchController.text = context
+        .read<UiViewStateService>()
+        .channelsSearchText;
     WidgetsBinding.instance.addPostFrameCallback((_) {
       context.read<MeshCoreConnector>().getChannels();
       _loadCommunities();
@@ -110,6 +110,7 @@ class _ChannelsScreenState extends State<ChannelsScreen>
   @override
   Widget build(BuildContext context) {
     final connector = context.watch<MeshCoreConnector>();
+    final viewState = context.watch<UiViewStateService>();
 
     final channelMessageStore = ChannelMessageStore();
     channelMessageStore.setPublicKeyHex = connector.selfPublicKeyHex;
@@ -205,6 +206,7 @@ class _ChannelsScreenState extends State<ChannelsScreen>
             final filteredChannels = _filterAndSortChannels(
               channels,
               connector,
+              viewState,
             );
 
             return Column(
@@ -219,17 +221,19 @@ class _ChannelsScreenState extends State<ChannelsScreen>
                       suffixIcon: Row(
                         mainAxisSize: MainAxisSize.min,
                         children: [
-                          if (_searchQuery.isNotEmpty)
+                          if (viewState.channelsSearchText.isNotEmpty)
                             IconButton(
                               icon: const Icon(Icons.clear),
                               onPressed: () {
+                                _searchDebounce?.cancel();
+                                _searchDebounce = null;
                                 _searchController.clear();
-                                setState(() {
-                                  _searchQuery = '';
-                                });
+                                context
+                                    .read<UiViewStateService>()
+                                    .setChannelsSearchText('');
                               },
                             ),
-                          _buildFilterButton(),
+                          _buildFilterButton(viewState),
                         ],
                       ),
                       border: OutlineInputBorder(
@@ -246,9 +250,9 @@ class _ChannelsScreenState extends State<ChannelsScreen>
                         const Duration(milliseconds: 300),
                         () {
                           if (!mounted) return;
-                          setState(() {
-                            _searchQuery = value.toLowerCase();
-                          });
+                          context
+                              .read<UiViewStateService>()
+                              .setChannelsSearchText(value);
                         },
                       );
                     },
@@ -283,8 +287,9 @@ class _ChannelsScreenState extends State<ChannelsScreen>
                             ),
                           ],
                         )
-                      : (_sortOption == ChannelSortOption.manual &&
-                            _searchQuery.isEmpty)
+                      : (viewState.channelsSortOption ==
+                                ChannelSortOption.manual &&
+                            viewState.channelsSearchText.isEmpty)
                       ? ReorderableListView.builder(
                           padding: const EdgeInsets.only(
                             left: 16,
@@ -584,59 +589,40 @@ class _ChannelsScreenState extends State<ChannelsScreen>
     await showDisconnectDialog(context, connector);
   }
 
-  Widget _buildFilterButton() {
-    const actionSortManual = 0;
-    const actionSortName = 1;
-    const actionSortLatest = 2;
-    const actionSortUnread = 3;
-
-    return SortFilterMenu(
+  Widget _buildFilterButton(UiViewStateService viewState) {
+    return SortFilterMenu<ChannelSortOption>(
       tooltip: context.l10n.listFilter_tooltip,
       sections: [
-        SortFilterMenuSection(
+        SortFilterMenuSection<ChannelSortOption>(
           title: context.l10n.channels_sortBy,
           options: [
-            SortFilterMenuOption(
-              value: actionSortManual,
+            SortFilterMenuOption<ChannelSortOption>(
+              value: ChannelSortOption.manual,
               label: context.l10n.channels_sortManual,
-              checked: _sortOption == ChannelSortOption.manual,
+              checked: viewState.channelsSortOption == ChannelSortOption.manual,
             ),
-            SortFilterMenuOption(
-              value: actionSortName,
+            SortFilterMenuOption<ChannelSortOption>(
+              value: ChannelSortOption.name,
               label: context.l10n.channels_sortAZ,
-              checked: _sortOption == ChannelSortOption.name,
+              checked: viewState.channelsSortOption == ChannelSortOption.name,
             ),
-            SortFilterMenuOption(
-              value: actionSortLatest,
+            SortFilterMenuOption<ChannelSortOption>(
+              value: ChannelSortOption.latestMessages,
               label: context.l10n.channels_sortLatestMessages,
-              checked: _sortOption == ChannelSortOption.latestMessages,
+              checked:
+                  viewState.channelsSortOption ==
+                  ChannelSortOption.latestMessages,
             ),
-            SortFilterMenuOption(
-              value: actionSortUnread,
+            SortFilterMenuOption<ChannelSortOption>(
+              value: ChannelSortOption.unread,
               label: context.l10n.channels_sortUnread,
-              checked: _sortOption == ChannelSortOption.unread,
+              checked: viewState.channelsSortOption == ChannelSortOption.unread,
             ),
           ],
         ),
       ],
-      onSelected: (action) {
-        setState(() {
-          switch (action) {
-            case actionSortManual:
-              _sortOption = ChannelSortOption.manual;
-              break;
-            case actionSortLatest:
-              _sortOption = ChannelSortOption.latestMessages;
-              break;
-            case actionSortUnread:
-              _sortOption = ChannelSortOption.unread;
-              break;
-            case actionSortName:
-            default:
-              _sortOption = ChannelSortOption.name;
-              break;
-          }
-        });
+      onSelected: (sortOption) {
+        viewState.setChannelsSortOption(sortOption);
       },
     );
   }
@@ -644,11 +630,14 @@ class _ChannelsScreenState extends State<ChannelsScreen>
   List<Channel> _filterAndSortChannels(
     List<Channel> channels,
     MeshCoreConnector connector,
+    UiViewStateService viewState,
   ) {
     var filtered = channels.where((channel) {
-      if (_searchQuery.isEmpty) return true;
+      if (viewState.channelsSearchText.isEmpty) return true;
       final label = _normalizeChannelName(channel);
-      return label.toLowerCase().contains(_searchQuery);
+      return label.toLowerCase().contains(
+        viewState.channelsSearchText.toLowerCase(),
+      );
     }).toList();
 
     int compareByName(Channel a, Channel b) {
@@ -657,7 +646,7 @@ class _ChannelsScreenState extends State<ChannelsScreen>
       return nameA.toLowerCase().compareTo(nameB.toLowerCase());
     }
 
-    switch (_sortOption) {
+    switch (viewState.channelsSortOption) {
       case ChannelSortOption.manual:
         break;
       case ChannelSortOption.latestMessages:

lib/screens/chat_screen.dart

@@ -858,7 +858,7 @@ class _ChatScreenState extends State<ChatScreen> {
                 builder: (context) => PathTraceMapScreen(
                   title: context.l10n.contacts_repeaterPathTrace,
                   path: Uint8List.fromList(pathBytes),
-                  flipPathRound: true,
+                  flipPathAround: true,
                   targetContact: widget.contact,
                 ),
               ),
@@ -1027,7 +1027,7 @@ class _ChatScreenState extends State<ChatScreen> {
     final currentPathLabel = _currentPathLabel(currentContact);
 
     // Filter out the current contact from available contacts
-    final availableContacts = connector.contacts
+    final availableContacts = connector.allContacts
         .where((c) => c != widget.contact)
         .toList();
 

lib/screens/contacts_screen.dart

@@ -13,8 +13,9 @@ import '../l10n/l10n.dart';
 import '../connector/meshcore_protocol.dart';
 import '../models/contact.dart';
 import '../models/contact_group.dart';
-import '../storage/contact_group_store.dart';
+import '../services/ui_view_state_service.dart';
 import '../utils/contact_search.dart';
+import '../storage/contact_group_store.dart';
 import '../utils/dialog_utils.dart';
 import '../utils/disconnect_navigation_mixin.dart';
 import '../utils/emoji_utils.dart';
@@ -48,12 +49,10 @@ class ContactsScreen extends StatefulWidget {
 class _ContactsScreenState extends State<ContactsScreen>
     with DisconnectNavigationMixin {
   final TextEditingController _searchController = TextEditingController();
-  String _searchQuery = '';
-  ContactSortOption _sortOption = ContactSortOption.lastSeen;
-  bool _showUnreadOnly = false;
-  ContactTypeFilter _typeFilter = ContactTypeFilter.all;
   final ContactGroupStore _groupStore = ContactGroupStore();
+  MeshCoreConnector? _scopeSyncConnector;
   List<ContactGroup> _groups = [];
+  String _loadedGroupScopeKeyHex = '';
   Timer? _searchDebounce;
 
   final Set<ContactOperationType> _pendingOperations = {};
@@ -63,6 +62,9 @@ class _ContactsScreenState extends State<ContactsScreen>
   @override
   void initState() {
     super.initState();
+    _searchController.text = context
+        .read<UiViewStateService>()
+        .contactsSearchText;
     _loadGroups();
     _setupFrameListener();
     _clearAdvertNotifications();
@@ -74,26 +76,84 @@ class _ContactsScreenState extends State<ContactsScreen>
     NotificationService().clearAdvertNotifications(contactIds);
   }
 
+  @override
+  void didChangeDependencies() {
+    super.didChangeDependencies();
+    final connector = context.read<MeshCoreConnector>();
+    if (!identical(_scopeSyncConnector, connector)) {
+      _scopeSyncConnector?.removeListener(_handleConnectorScopeChange);
+      _scopeSyncConnector = connector;
+      _scopeSyncConnector?.addListener(_handleConnectorScopeChange);
+    }
+    _handleConnectorScopeChange();
+  }
+
   @override
   void dispose() {
     _searchDebounce?.cancel();
     _searchController.dispose();
     _frameSubscription?.cancel();
+    _scopeSyncConnector?.removeListener(_handleConnectorScopeChange);
     super.dispose();
   }
 
+  void _handleConnectorScopeChange() {
+    final connector = _scopeSyncConnector;
+    if (connector == null) return;
+    _syncGroupScopeIfNeeded(connector);
+  }
+
   Future<void> _loadGroups() async {
+    final selfPublicKeyHex = context.read<MeshCoreConnector>().selfPublicKeyHex;
+    if (selfPublicKeyHex.isEmpty) {
+      return;
+    }
+    _groupStore.setPublicKeyHex = selfPublicKeyHex;
     final groups = await _groupStore.loadGroups();
     if (!mounted) return;
     setState(() {
+      _loadedGroupScopeKeyHex = selfPublicKeyHex;
       _groups = groups;
+      _ensureValidSelectedGroup();
     });
   }
 
   Future<void> _saveGroups() async {
+    final selfPublicKeyHex = context.read<MeshCoreConnector>().selfPublicKeyHex;
+    if (selfPublicKeyHex.isEmpty) {
+      return;
+    }
+    _groupStore.setPublicKeyHex = selfPublicKeyHex;
     await _groupStore.saveGroups(_groups);
   }
 
+  bool _hasGroupStoreScope(MeshCoreConnector connector) {
+    return connector.selfPublicKeyHex.isNotEmpty;
+  }
+
+  void _syncGroupScopeIfNeeded(MeshCoreConnector connector) {
+    final selfPublicKeyHex = connector.selfPublicKeyHex;
+    if (selfPublicKeyHex.isEmpty ||
+        selfPublicKeyHex == _loadedGroupScopeKeyHex) {
+      return;
+    }
+    _loadGroups();
+  }
+
+  void _collapseContactsSearch(UiViewStateService viewState) {
+    _searchDebounce?.cancel();
+    _searchDebounce = null;
+    _searchController.clear();
+    viewState.setContactsSearchText('');
+    viewState.setContactsSearchExpanded(false);
+  }
+
+  void _showGroupsUnavailableMessage(BuildContext context) {
+    ScaffoldMessenger.of(
+      context,
+    ).showSnackBar(SnackBar(content: Text(context.l10n.common_loading)));
+  }
+
   void _setupFrameListener() {
     final connector = Provider.of<MeshCoreConnector>(context, listen: false);
     // Listen for incoming text messages from the repeater
@@ -383,31 +443,166 @@ class _ContactsScreenState extends State<ContactsScreen>
     await showDisconnectDialog(context, connector);
   }
 
-  Widget _buildFilterButton(BuildContext context, MeshCoreConnector connector) {
+  ContactGroup? _selectedGroupForName(String selectedGroupName) {
+    if (selectedGroupName == contactsAllGroupsValue) return null;
+    for (final group in _groups) {
+      if (group.name == selectedGroupName) return group;
+    }
+    return null;
+  }
+
+  void _ensureValidSelectedGroup() {
+    final viewState = context.read<UiViewStateService>();
+    if (viewState.contactsSelectedGroupName == contactsAllGroupsValue) return;
+    final exists = _groups.any(
+      (group) => group.name == viewState.contactsSelectedGroupName,
+    );
+    if (!exists) {
+      viewState.setContactsSelectedGroupName(contactsAllGroupsValue);
+    }
+  }
+
+  void _closeDropdownAndRun(BuildContext popupContext, VoidCallback action) {
+    final route = ModalRoute.of(popupContext);
+    if (route != null && route.isCurrent) {
+      Navigator.of(popupContext).pop();
+    }
+    WidgetsBinding.instance.addPostFrameCallback((_) {
+      if (!mounted) return;
+      action();
+    });
+  }
+
+  Widget _buildFilterButton(
+    BuildContext context,
+    UiViewStateService viewState,
+  ) {
     return ContactsFilterMenu(
-      sortOption: _sortOption,
-      typeFilter: _typeFilter,
-      showUnreadOnly: _showUnreadOnly,
+      sortOption: viewState.contactsSortOption,
+      typeFilter: viewState.contactsTypeFilter,
+      showUnreadOnly: viewState.contactsShowUnreadOnly,
       onSortChanged: (value) {
-        setState(() {
-          _sortOption = value;
-        });
+        viewState.setContactsSortOption(value);
       },
       onTypeFilterChanged: (value) {
-        setState(() {
-          _typeFilter = value;
-        });
+        viewState.setContactsTypeFilter(value);
       },
       onUnreadOnlyChanged: (value) {
-        setState(() {
-          _showUnreadOnly = value;
-        });
+        viewState.setContactsShowUnreadOnly(value);
       },
-      onNewGroup: () => _showGroupEditor(context, connector.contacts),
+    );
+  }
+
+  Widget _buildGroupButton(
+    BuildContext context,
+    MeshCoreConnector connector,
+    UiViewStateService viewState,
+    List<Contact> contacts,
+    List<ContactGroup> sortedGroups,
+  ) {
+    final canManageGroups = _hasGroupStoreScope(connector);
+    final selectedGroupName =
+        _selectedGroupForName(viewState.contactsSelectedGroupName)?.name ??
+        context.l10n.listFilter_all;
+    final double menuWidth = (MediaQuery.sizeOf(context).width - 16).clamp(
+      0.0,
+      double.infinity,
+    );
+
+    return PopupMenuButton<String>(
+      position: PopupMenuPosition.under,
+      constraints: BoxConstraints.tightFor(width: menuWidth),
+      onSelected: (String value) {
+        viewState.setContactsSelectedGroupName(value);
+      },
+      itemBuilder: (menuContext) => [
+        PopupMenuItem<String>(
+          value: contactsAllGroupsValue,
+          child: Row(
+            mainAxisAlignment: MainAxisAlignment.spaceBetween,
+            children: [
+              Text(menuContext.l10n.listFilter_all),
+              IconButton(
+                tooltip: menuContext.l10n.contacts_newGroup,
+                icon: const Icon(Icons.group_add, size: 20),
+                onPressed: canManageGroups
+                    ? () => _closeDropdownAndRun(
+                        menuContext,
+                        () => _showGroupEditor(this.context, contacts),
+                      )
+                    : () => _closeDropdownAndRun(
+                        menuContext,
+                        () => _showGroupsUnavailableMessage(this.context),
+                      ),
+              ),
+            ],
+          ),
+        ),
+        ...sortedGroups.map((group) {
+          return PopupMenuItem<String>(
+            value: group.name,
+            child: Row(
+              mainAxisAlignment: MainAxisAlignment.spaceBetween,
+              children: [
+                Expanded(
+                  child: Text(group.name, overflow: TextOverflow.ellipsis),
+                ),
+                IconButton(
+                  tooltip: menuContext.l10n.contacts_editGroup,
+                  icon: const Icon(Icons.edit, size: 20),
+                  onPressed: canManageGroups
+                      ? () => _closeDropdownAndRun(
+                          menuContext,
+                          () => _showGroupEditor(
+                            this.context,
+                            contacts,
+                            group: group,
+                          ),
+                        )
+                      : () => _closeDropdownAndRun(
+                          menuContext,
+                          () => _showGroupsUnavailableMessage(this.context),
+                        ),
+                ),
+                const SizedBox(width: 8),
+                IconButton(
+                  tooltip: menuContext.l10n.contacts_deleteGroup,
+                  icon: const Icon(Icons.delete, size: 20, color: Colors.red),
+                  onPressed: canManageGroups
+                      ? () => _closeDropdownAndRun(
+                          menuContext,
+                          () => _confirmDeleteGroup(this.context, group),
+                        )
+                      : () => _closeDropdownAndRun(
+                          menuContext,
+                          () => _showGroupsUnavailableMessage(this.context),
+                        ),
+                ),
+              ],
+            ),
+          );
+        }),
+      ],
+      child: SizedBox(
+        height: 48,
+        child: Padding(
+          padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 10),
+          child: Row(
+            children: [
+              Expanded(
+                child: Text(selectedGroupName, overflow: TextOverflow.ellipsis),
+              ),
+              const SizedBox(width: 8),
+              const Icon(Icons.arrow_drop_down),
+            ],
+          ),
+        ),
+      ),
     );
   }
 
   Widget _buildContactsBody(BuildContext context, MeshCoreConnector connector) {
+    final viewState = context.watch<UiViewStateService>();
     final contacts = connector.contacts;
     final shouldShowStartupSpinner =
         contacts.isEmpty &&
@@ -429,92 +624,171 @@ class _ContactsScreenState extends State<ContactsScreen>
       );
     }
 
-    final filteredAndSorted = _filterAndSortContacts(contacts, connector);
-    final filteredGroups = _showUnreadOnly
-        ? const <ContactGroup>[]
-        : _filterAndSortGroups(_groups, contacts);
+    final filteredAndSorted = _filterAndSortContacts(
+      contacts,
+      connector,
+      viewState,
+    );
 
     String hintText = "";
 
-    switch (_typeFilter) {
+    switch (viewState.contactsTypeFilter) {
       case ContactTypeFilter.all:
         hintText = context.l10n.contacts_searchContacts(
           filteredAndSorted.length,
-          _showUnreadOnly ? " ${context.l10n.contacts_unread}" : "",
+          viewState.contactsShowUnreadOnly
+              ? " ${context.l10n.contacts_unread}"
+              : "",
         );
         break;
       case ContactTypeFilter.users:
         hintText = context.l10n.contacts_searchUsers(
           filteredAndSorted.length,
-          _showUnreadOnly ? " ${context.l10n.contacts_unread}" : "",
+          viewState.contactsShowUnreadOnly
+              ? " ${context.l10n.contacts_unread}"
+              : "",
         );
         break;
       case ContactTypeFilter.repeaters:
         hintText = context.l10n.contacts_searchRepeaters(
           filteredAndSorted.length,
-          _showUnreadOnly ? " ${context.l10n.contacts_unread}" : "",
+          viewState.contactsShowUnreadOnly
+              ? " ${context.l10n.contacts_unread}"
+              : "",
         );
         break;
       case ContactTypeFilter.rooms:
         hintText = context.l10n.contacts_searchRoomServers(
           filteredAndSorted.length,
-          _showUnreadOnly ? " ${context.l10n.contacts_unread}" : "",
+          viewState.contactsShowUnreadOnly
+              ? " ${context.l10n.contacts_unread}"
+              : "",
         );
         break;
       case ContactTypeFilter.favorites:
         hintText = context.l10n.contacts_searchFavorites(
           filteredAndSorted.length,
-          _showUnreadOnly ? " ${context.l10n.contacts_unread}" : "",
+          viewState.contactsShowUnreadOnly
+              ? " ${context.l10n.contacts_unread}"
+              : "",
         );
         break;
     }
 
+    final groupsByName = <String, ContactGroup>{};
+    for (final group in _groups) {
+      groupsByName.putIfAbsent(group.name, () => group);
+    }
+    final sortedGroups = groupsByName.values.toList()
+      ..sort((a, b) => a.name.toLowerCase().compareTo(b.name.toLowerCase()));
+
+    final screenWidth = MediaQuery.sizeOf(context).width;
+    final searchExpandedWidth = (screenWidth * 0.52).clamp(
+      97.0,
+      double.infinity,
+    ); // allow expansion up to 52% of screen width, but not less than the collapsed width
+    final searchCollapsedWidth = (screenWidth * 0.22).clamp(
+      97.0,
+      120.0,
+    ); //two 48px icon buttons + 1px divider
+
     return Column(
       children: [
         Padding(
           padding: const EdgeInsets.all(8.0),
-          child: TextField(
-            controller: _searchController,
-            decoration: InputDecoration(
-              hintText: hintText,
-              prefixIcon: const Icon(Icons.search),
-              suffixIcon: Row(
-                mainAxisSize: MainAxisSize.min,
-                children: [
-                  if (_searchQuery.isNotEmpty)
-                    IconButton(
-                      icon: const Icon(Icons.clear),
-                      onPressed: () {
-                        _searchController.clear();
-                        setState(() {
-                          _searchQuery = '';
-                        });
-                      },
+          child: Row(
+            children: [
+              Expanded(
+                child: _buildGroupButton(
+                  context,
+                  connector,
+                  viewState,
+                  contacts,
+                  sortedGroups,
+                ),
+              ),
+              const SizedBox(width: 8),
+              AnimatedContainer(
+                duration: const Duration(milliseconds: 220),
+                curve: Curves.easeOutCubic,
+                width: viewState.contactsSearchExpanded
+                    ? searchExpandedWidth
+                    : searchCollapsedWidth,
+                height: 48,
+                child: DecoratedBox(
+                  decoration: BoxDecoration(
+                    border: Border.all(
+                      color: Theme.of(context).colorScheme.outline,
                     ),
-                  _buildFilterButton(context, connector),
-                ],
+                    borderRadius: BorderRadius.circular(12),
+                  ),
+                  child: Row(
+                    children: [
+                      Expanded(
+                        child: viewState.contactsSearchExpanded
+                            ? TextField(
+                                controller: _searchController,
+                                autofocus: true,
+                                decoration: InputDecoration(
+                                  hintText: hintText,
+                                  border: InputBorder.none,
+                                  contentPadding: const EdgeInsets.symmetric(
+                                    horizontal: 12,
+                                    vertical: 10,
+                                  ),
+                                ),
+                                onChanged: (value) {
+                                  _searchDebounce?.cancel();
+                                  _searchDebounce = Timer(
+                                    const Duration(milliseconds: 300),
+                                    () {
+                                      if (!mounted) return;
+                                      context
+                                          .read<UiViewStateService>()
+                                          .setContactsSearchText(value);
+                                    },
+                                  );
+                                },
+                              )
+                            : const SizedBox.shrink(),
+                      ),
+                      SizedBox(
+                        width: 48,
+                        height: 48,
+                        child: IconButton(
+                          onPressed: () {
+                            if (viewState.contactsSearchExpanded) {
+                              _collapseContactsSearch(viewState);
+                              return;
+                            }
+                            viewState.setContactsSearchExpanded(true);
+                          },
+                          icon: Icon(
+                            viewState.contactsSearchExpanded
+                                ? Icons.close
+                                : Icons.search,
+                          ),
+                        ),
+                      ),
+                      Container(
+                        width: 1,
+                        height: 24,
+                        color: Theme.of(context).colorScheme.outlineVariant,
+                      ),
+                      SizedBox(
+                        width: 48,
+                        height: 48,
+                        child: _buildFilterButton(context, viewState),
+                      ),
+                    ],
+                  ),
+                ),
               ),
-              border: OutlineInputBorder(
-                borderRadius: BorderRadius.circular(12),
-              ),
-              contentPadding: const EdgeInsets.symmetric(
-                horizontal: 16,
-                vertical: 12,
-              ),
-            ),
-            onChanged: (value) {
-              _searchDebounce?.cancel();
-              _searchDebounce = Timer(const Duration(milliseconds: 300), () {
-                if (!mounted) return;
-                setState(() {
-                  _searchQuery = value.toLowerCase();
-                });
-              });
-            },
+            ],
           ),
         ),
         Expanded(
-          child: filteredAndSorted.isEmpty && filteredGroups.isEmpty
+          child: filteredAndSorted.isEmpty
               ? Center(
                   child: Column(
                     mainAxisAlignment: MainAxisAlignment.center,
@@ -522,7 +796,7 @@ class _ContactsScreenState extends State<ContactsScreen>
                       Icon(Icons.search_off, size: 64, color: Colors.grey[400]),
                       const SizedBox(height: 16),
                       Text(
-                        _showUnreadOnly
+                        viewState.contactsShowUnreadOnly
                             ? context.l10n.contacts_noUnreadContacts
                             : context.l10n.contacts_noContactsFound,
                         style: TextStyle(fontSize: 16, color: Colors.grey[600]),
@@ -533,14 +807,9 @@ class _ContactsScreenState extends State<ContactsScreen>
               : RefreshIndicator(
                   onRefresh: () => connector.getContacts(),
                   child: ListView.builder(
-                    itemCount: filteredGroups.length + filteredAndSorted.length,
+                    itemCount: filteredAndSorted.length,
                     itemBuilder: (context, index) {
-                      if (index < filteredGroups.length) {
-                        final group = filteredGroups[index];
-                        return _buildGroupTile(context, group, contacts);
-                      }
-                      final contact =
-                          filteredAndSorted[index - filteredGroups.length];
+                      final contact = filteredAndSorted[index];
                       final unreadCount = connector.getUnreadCountForContact(
                         contact,
                       );
@@ -561,55 +830,26 @@ class _ContactsScreenState extends State<ContactsScreen>
     );
   }
 
-  List<ContactGroup> _filterAndSortGroups(
-    List<ContactGroup> groups,
-    List<Contact> contacts,
-  ) {
-    final query = _searchQuery.trim().toLowerCase();
-    final contactsByKey = <String, Contact>{};
-    for (final contact in contacts) {
-      contactsByKey[contact.publicKeyHex] = contact;
-    }
-
-    final filtered = groups
-        .where((group) {
-          if (query.isEmpty) return true;
-          if (group.name.toLowerCase().contains(query)) return true;
-          for (final key in group.memberKeys) {
-            final contact = contactsByKey[key];
-            if (contact != null && matchesContactQuery(contact, query)) {
-              return true;
-            }
-          }
-          return false;
-        })
-        .where((group) {
-          if (_typeFilter == ContactTypeFilter.all) return true;
-          // Groups don't have a favorite flag, so hide them under favorites filter
-          if (_typeFilter == ContactTypeFilter.favorites) return false;
-          for (final key in group.memberKeys) {
-            final contact = contactsByKey[key];
-            if (contact != null && _matchesTypeFilter(contact)) return true;
-          }
-          return false;
-        })
-        .toList();
-
-    filtered.sort(
-      (a, b) => a.name.toLowerCase().compareTo(b.name.toLowerCase()),
-    );
-    return filtered;
-  }
-
   List<Contact> _filterAndSortContacts(
     List<Contact> contacts,
     MeshCoreConnector connector,
+    UiViewStateService viewState,
   ) {
     var filtered = contacts.where((contact) {
-      if (_searchQuery.isEmpty) return true;
-      return matchesContactQuery(contact, _searchQuery);
+      if (viewState.contactsSearchText.isEmpty) return true;
+      return matchesContactQuery(contact, viewState.contactsSearchText);
     }).toList();
 
+    final selectedGroup = _selectedGroupForName(
+      viewState.contactsSelectedGroupName,
+    );
+    if (selectedGroup != null) {
+      final memberKeys = selectedGroup.memberKeys.toSet();
+      filtered = filtered
+          .where((contact) => memberKeys.contains(contact.publicKeyHex))
+          .toList();
+    }
+
     // Filter out own node from the list
     if (connector.selfPublicKey != null) {
       final selfPubKeyHex = pubKeyToHex(connector.selfPublicKey!);
@@ -618,17 +858,22 @@ class _ContactsScreenState extends State<ContactsScreen>
       }).toList();
     }
 
-    if (_typeFilter != ContactTypeFilter.all) {
-      filtered = filtered.where(_matchesTypeFilter).toList();
+    if (viewState.contactsTypeFilter != ContactTypeFilter.all) {
+      filtered = filtered
+          .where(
+            (contact) =>
+                _matchesTypeFilter(contact, viewState.contactsTypeFilter),
+          )
+          .toList();
     }
 
-    if (_showUnreadOnly) {
+    if (viewState.contactsShowUnreadOnly) {
       filtered = filtered.where((contact) {
         return connector.getUnreadCountForContact(contact) > 0;
       }).toList();
     }
 
-    switch (_sortOption) {
+    switch (viewState.contactsSortOption) {
       case ContactSortOption.lastSeen:
         filtered.sort(
           (a, b) => _resolveLastSeen(b).compareTo(_resolveLastSeen(a)),
@@ -657,8 +902,8 @@ class _ContactsScreenState extends State<ContactsScreen>
     return filtered;
   }
 
-  bool _matchesTypeFilter(Contact contact) {
-    switch (_typeFilter) {
+  bool _matchesTypeFilter(Contact contact, ContactTypeFilter typeFilter) {
+    switch (typeFilter) {
       case ContactTypeFilter.all:
         return true;
       case ContactTypeFilter.favorites:
@@ -679,57 +924,6 @@ class _ContactsScreenState extends State<ContactsScreen>
         : contact.lastSeen;
   }
 
-  Widget _buildGroupTile(
-    BuildContext context,
-    ContactGroup group,
-    List<Contact> contacts,
-  ) {
-    final memberContacts = _resolveGroupContacts(group, contacts);
-    final subtitle = _formatGroupMembers(context, memberContacts);
-    return ListTile(
-      leading: const CircleAvatar(
-        backgroundColor: Colors.teal,
-        child: Icon(Icons.group, color: Colors.white, size: 20),
-      ),
-      title: Text(group.name),
-      subtitle: Text(subtitle),
-      trailing: Text(
-        memberContacts.length.toString(),
-        style: TextStyle(fontSize: 12, color: Colors.grey[600]),
-      ),
-      onTap: () => _showGroupOptions(context, group, contacts),
-      onLongPress: () => _showGroupOptions(context, group, contacts),
-    );
-  }
-
-  List<Contact> _resolveGroupContacts(
-    ContactGroup group,
-    List<Contact> contacts,
-  ) {
-    final byKey = <String, Contact>{};
-    for (final contact in contacts) {
-      byKey[contact.publicKeyHex] = contact;
-    }
-    final resolved = <Contact>[];
-    for (final key in group.memberKeys) {
-      final contact = byKey[key];
-      if (contact != null) {
-        resolved.add(contact);
-      }
-    }
-    resolved.sort(
-      (a, b) => a.name.toLowerCase().compareTo(b.name.toLowerCase()),
-    );
-    return resolved;
-  }
-
-  String _formatGroupMembers(BuildContext context, List<Contact> members) {
-    if (members.isEmpty) return context.l10n.contacts_noMembers;
-    final names = members.map((c) => c.name).toList();
-    if (names.length <= 2) return names.join(', ');
-    return '${names.take(2).join(', ')} +${names.length - 2}';
-  }
-
   void _openChat(BuildContext context, Contact contact) {
     // Check if this is a repeater
     if (contact.type == advTypeRepeater) {
@@ -807,58 +1001,11 @@ class _ContactsScreenState extends State<ContactsScreen>
     );
   }
 
-  void _showGroupOptions(
-    BuildContext context,
-    ContactGroup group,
-    List<Contact> contacts,
-  ) {
-    final members = _resolveGroupContacts(group, contacts);
-    showModalBottomSheet(
-      context: context,
-      builder: (sheetContext) => SafeArea(
-        child: SingleChildScrollView(
-          child: Column(
-            mainAxisSize: MainAxisSize.min,
-            children: [
-              ListTile(
-                leading: const Icon(Icons.edit),
-                title: Text(context.l10n.contacts_editGroup),
-                onTap: () {
-                  Navigator.pop(sheetContext);
-                  _showGroupEditor(context, contacts, group: group);
-                },
-              ),
-              ListTile(
-                leading: const Icon(Icons.delete, color: Colors.red),
-                title: Text(
-                  context.l10n.contacts_deleteGroup,
-                  style: const TextStyle(color: Colors.red),
-                ),
-                onTap: () {
-                  Navigator.pop(sheetContext);
-                  _confirmDeleteGroup(context, group);
-                },
-              ),
-              if (members.isNotEmpty) const Divider(),
-              ...members.map((member) {
-                return ListTile(
-                  leading: const Icon(Icons.person),
-                  title: Text(member.name),
-                  subtitle: Text(member.typeLabel),
-                  onTap: () {
-                    Navigator.pop(sheetContext);
-                    _openChat(context, member);
-                  },
-                );
-              }),
-            ],
-          ),
-        ),
-      ),
-    );
-  }
-
   void _confirmDeleteGroup(BuildContext context, ContactGroup group) {
+    if (!_hasGroupStoreScope(context.read<MeshCoreConnector>())) {
+      _showGroupsUnavailableMessage(context);
+      return;
+    }
     showDialog(
       context: context,
       builder: (dialogContext) => AlertDialog(
@@ -874,6 +1021,7 @@ class _ContactsScreenState extends State<ContactsScreen>
               Navigator.pop(dialogContext);
               setState(() {
                 _groups.removeWhere((g) => g.name == group.name);
+                _ensureValidSelectedGroup();
               });
               await _saveGroups();
             },
@@ -892,6 +1040,10 @@ class _ContactsScreenState extends State<ContactsScreen>
     List<Contact> contacts, {
     ContactGroup? group,
   }) {
+    if (!_hasGroupStoreScope(context.read<MeshCoreConnector>())) {
+      _showGroupsUnavailableMessage(context);
+      return;
+    }
     final isEditing = group != null;
     final nameController = TextEditingController(text: group?.name ?? '');
     final selectedKeys = <String>{...group?.memberKeys ?? []};
@@ -918,64 +1070,70 @@ class _ContactsScreenState extends State<ContactsScreen>
             ),
             content: SizedBox(
               width: double.maxFinite,
-              child: Column(
-                mainAxisSize: MainAxisSize.min,
-                children: [
-                  TextField(
-                    controller: nameController,
-                    decoration: InputDecoration(
-                      labelText: context.l10n.contacts_groupName,
-                      border: const OutlineInputBorder(),
+              child: ConstrainedBox(
+                constraints: BoxConstraints(
+                  maxHeight: MediaQuery.of(context).size.height * 0.8,
+                ),
+                child: Column(
+                  mainAxisSize: MainAxisSize.min,
+                  children: [
+                    TextField(
+                      controller: nameController,
+                      decoration: InputDecoration(
+                        labelText: context.l10n.contacts_groupName,
+                        border: const OutlineInputBorder(),
+                      ),
                     ),
-                  ),
-                  const SizedBox(height: 12),
-                  TextField(
-                    decoration: InputDecoration(
-                      hintText: context.l10n.contacts_filterContacts,
-                      prefixIcon: const Icon(Icons.search),
-                      border: const OutlineInputBorder(),
-                      isDense: true,
+                    const SizedBox(height: 12),
+                    TextField(
+                      decoration: InputDecoration(
+                        hintText: context.l10n.contacts_filterContacts,
+                        prefixIcon: const Icon(Icons.search),
+                        border: const OutlineInputBorder(),
+                        isDense: true,
+                      ),
+                      onChanged: (value) {
+                        setDialogState(() {
+                          filterQuery = value.toLowerCase();
+                        });
+                      },
                     ),
-                    onChanged: (value) {
-                      setDialogState(() {
-                        filterQuery = value.toLowerCase();
-                      });
-                    },
-                  ),
-                  const SizedBox(height: 12),
-                  SizedBox(
-                    height: 240,
-                    child: filteredContacts.isEmpty
-                        ? Center(
-                            child: Text(
-                              context.l10n.contacts_noContactsMatchFilter,
+                    const SizedBox(height: 12),
+                    Expanded(
+                      child: filteredContacts.isEmpty
+                          ? Center(
+                              child: Text(
+                                context.l10n.contacts_noContactsMatchFilter,
+                              ),
+                            )
+                          : ListView.builder(
+                              itemCount: filteredContacts.length,
+                              itemBuilder: (context, index) {
+                                final contact = filteredContacts[index];
+                                final isSelected = selectedKeys.contains(
+                                  contact.publicKeyHex,
+                                );
+                                return CheckboxListTile(
+                                  value: isSelected,
+                                  title: Text(contact.name),
+                                  subtitle: Text(contact.typeLabel),
+                                  onChanged: (value) {
+                                    setDialogState(() {
+                                      if (value == true) {
+                                        selectedKeys.add(contact.publicKeyHex);
+                                      } else {
+                                        selectedKeys.remove(
+                                          contact.publicKeyHex,
+                                        );
+                                      }
+                                    });
+                                  },
+                                );
+                              },
                             ),
-                          )
-                        : ListView.builder(
-                            itemCount: filteredContacts.length,
-                            itemBuilder: (context, index) {
-                              final contact = filteredContacts[index];
-                              final isSelected = selectedKeys.contains(
-                                contact.publicKeyHex,
-                              );
-                              return CheckboxListTile(
-                                value: isSelected,
-                                title: Text(contact.name),
-                                subtitle: Text(contact.typeLabel),
-                                onChanged: (value) {
-                                  setDialogState(() {
-                                    if (value == true) {
-                                      selectedKeys.add(contact.publicKeyHex);
-                                    } else {
-                                      selectedKeys.remove(contact.publicKeyHex);
-                                    }
-                                  });
-                                },
-                              );
-                            },
-                          ),
-                  ),
-                ],
+                    ),
+                  ],
+                ),
               ),
             ),
             actions: [
@@ -994,6 +1152,15 @@ class _ContactsScreenState extends State<ContactsScreen>
                     );
                     return;
                   }
+                  if (name.toLowerCase() ==
+                      contactsAllGroupsValue.toLowerCase()) {
+                    ScaffoldMessenger.of(context).showSnackBar(
+                      SnackBar(
+                        content: Text(context.l10n.contacts_groupNameReserved),
+                      ),
+                    );
+                    return;
+                  }
                   final exists = _groups.any((g) {
                     if (isEditing && g.name == group.name) return false;
                     return g.name.toLowerCase() == name.toLowerCase();
@@ -1009,15 +1176,21 @@ class _ContactsScreenState extends State<ContactsScreen>
                     return;
                   }
                   setState(() {
+                    final viewState = context.read<UiViewStateService>();
                     if (isEditing) {
                       final index = _groups.indexWhere(
                         (g) => g.name == group.name,
                       );
                       if (index != -1) {
+                        final wasSelected =
+                            viewState.contactsSelectedGroupName == group.name;
                         _groups[index] = ContactGroup(
                           name: name,
                           memberKeys: selectedKeys.toList(),
                         );
+                        if (wasSelected) {
+                          viewState.setContactsSelectedGroupName(name);
+                        }
                       }
                     } else {
                       _groups.add(
@@ -1026,7 +1199,9 @@ class _ContactsScreenState extends State<ContactsScreen>
                           memberKeys: selectedKeys.toList(),
                         ),
                       );
+                      viewState.setContactsSelectedGroupName(name);
                     }
+                    _ensureValidSelectedGroup();
                   });
                   await _saveGroups();
                   if (dialogContext.mounted) {
@@ -1064,7 +1239,7 @@ class _ContactsScreenState extends State<ContactsScreen>
             if (isRepeater) ...[
               ListTile(
                 leading: const Icon(Icons.radar, color: Colors.green),
-                title: contact.pathLength > 0
+                title: contact.pathBytesForDisplay.isNotEmpty
                     ? Text(context.l10n.contacts_pathTrace)
                     : Text(context.l10n.contacts_ping),
                 onTap: () {
@@ -1072,10 +1247,12 @@ class _ContactsScreenState extends State<ContactsScreen>
                     context,
                     MaterialPageRoute(
                       builder: (context) => PathTraceMapScreen(
-                        title: contact.pathLength > 0
+                        title: contact.pathBytesForDisplay.isNotEmpty
                             ? context.l10n.contacts_repeaterPathTrace
                             : context.l10n.contacts_repeaterPing,
-                        path: contact.traceRouteBytes ?? Uint8List(0),
+                        path: contact.pathBytesForDisplay,
+                        flipPathAround: true,
+                        targetContact: contact,
                       ),
                     ),
                   );
@@ -1100,10 +1277,12 @@ class _ContactsScreenState extends State<ContactsScreen>
                     context,
                     MaterialPageRoute(
                       builder: (context) => PathTraceMapScreen(
-                        title: contact.pathLength > 0
+                        title: contact.pathBytesForDisplay.isNotEmpty
                             ? context.l10n.contacts_roomPathTrace
                             : context.l10n.contacts_roomPing,
-                        path: contact.traceRouteBytes ?? Uint8List(0),
+                        path: contact.pathBytesForDisplay,
+                        flipPathAround: contact.pathBytesForDisplay.isNotEmpty,
+                        targetContact: contact,
                       ),
                     ),
                   );
@@ -1145,7 +1324,8 @@ class _ContactsScreenState extends State<ContactsScreen>
                           title: context.l10n.contacts_pathTraceTo(
                             contact.name,
                           ),
-                          path: contact.traceRouteBytes ?? Uint8List(0),
+                          path: contact.pathBytesForDisplay,
+                          flipPathAround: true,
                           targetContact: contact,
                         ),
                       ),

lib/screens/map_screen.dart

@@ -137,10 +137,7 @@ class _MapScreenState extends State<MapScreen> {
       builder: (context, connector, settingsService, pathHistory, child) {
         final tileCache = context.read<MapTileCacheService>();
         final settings = settingsService.settings;
-        final allContacts = <Contact>[
-          ...connector.contacts,
-          ...connector.discoveredContacts.where((c) => !c.isActive),
-        ];
+        final allContacts = connector.allContacts;
 
         final contacts = settings.mapShowDiscoveryContacts
             ? allContacts
@@ -179,20 +176,13 @@ class _MapScreenState extends State<MapScreen> {
 
         // Filter by location
         final contactsWithLocation = filteredByKeyPrefix.where((c) {
-          if (!c.hasLocation) {
-            return false;
-          }
-          return _checkLocationPlausibility(c.latitude!, c.longitude!);
+          return c.hasLocation;
         }).toList();
 
         // All contacts with a known location — used as anchors regardless of
         // time/key-prefix filters so that repeaters are always available.
         final allContactsWithLocation = allContacts
-            .where(
-              (c) =>
-                  c.hasLocation &&
-                  _checkLocationPlausibility(c.latitude!, c.longitude!),
-            )
+            .where((c) => c.hasLocation)
             .toList();
 
         // Compute guessed locations with caching

lib/screens/neighbors_screen.dart

@@ -124,10 +124,7 @@ class _NeighborsScreenState extends State<NeighborsScreen> {
 
   void _handleNeighborsResponse(MeshCoreConnector connector, Uint8List frame) {
     final buffer = BufferReader(frame);
-    final contacts = <Contact>[
-      ...connector.contacts,
-      ...connector.discoveredContacts,
-    ];
+    final contacts = connector.allContacts;
     try {
       final neighborCount = buffer.readUInt16LE();
       final parsedNeighbors = parseNeighborsData(buffer, buffer.readUInt16LE());

lib/screens/path_trace_map.dart

@@ -52,8 +52,8 @@ class PathTraceMapScreen extends StatefulWidget {
   final String title;
   final Uint8List path;
   final int? repeaterId;
-  final bool flipPathRound;
-  final bool reversePathRound;
+  final bool flipPathAround;
+  final bool reversePathAround;
   final Contact? targetContact;
 
   const PathTraceMapScreen({
@@ -61,8 +61,8 @@ class PathTraceMapScreen extends StatefulWidget {
     required this.title,
     required this.path,
     this.repeaterId,
-    this.flipPathRound = false,
-    this.reversePathRound = false,
+    this.flipPathAround = false,
+    this.reversePathAround = false,
     this.targetContact,
   });
 
@@ -93,6 +93,7 @@ class _PathTraceMapScreenState extends State<PathTraceMapScreen> {
   ValueKey<String> _mapKey = const ValueKey('initial');
   double _pathDistanceMeters = 0.0;
   bool _showNodeLabels = true;
+  Contact? _targetContact;
 
   String _formatPathPrefixes(Uint8List pathBytes) {
     return pathBytes
@@ -158,21 +159,16 @@ class _PathTraceMapScreenState extends State<PathTraceMapScreen> {
       });
     }
 
-    final Uint8List path;
-
-    Uint8List pathTmp = widget.reversePathRound
+    final pathTmp = widget.reversePathAround
         ? Uint8List.fromList(widget.path.reversed.toList())
         : widget.path;
 
-    if (widget.flipPathRound) {
-      path = buildPath(pathTmp);
-    } else {
-      path = pathTmp;
-    }
+    final path = widget.flipPathAround ? buildPath(pathTmp) : pathTmp;
 
     appLogger.info(
       'Initiating path trace with path: ${_formatPathPrefixes(path)}',
       tag: 'PathTraceMapScreen',
+      noNotify: !mounted,
     );
 
     final connector = Provider.of<MeshCoreConnector>(context, listen: false);
@@ -263,10 +259,7 @@ class _PathTraceMapScreenState extends State<PathTraceMapScreen> {
           .toList();
 
       Map<int, Contact> pathContacts = {};
-      final contacts = <Contact>[
-        ...connector.contacts,
-        ...connector.discoveredContacts,
-      ];
+      final contacts = connector.allContacts;
       contacts.where((c) => c.type != advTypeChat).forEach((repeater) {
         for (var repeaterData in pathData) {
           if (listEquals(
@@ -312,18 +305,21 @@ class _PathTraceMapScreenState extends State<PathTraceMapScreen> {
         // Compute endpoint position for the target contact.
         LatLng? targetPos;
         bool targetGuessed = false;
-        final target = widget.targetContact;
-        if (target != null) {
-          if (target.hasLocation) {
-            targetPos = LatLng(target.latitude!, target.longitude!);
-          } else if (pathData.isNotEmpty) {
+        _targetContact = widget.targetContact;
+
+        if (_targetContact != null) {
+          final tc = _targetContact!;
+          if (tc.hasLocation) {
+            targetPos = LatLng(tc.latitude!, tc.longitude!);
+          } else if (widget.path.length > 1) {
             // Infer from the last hop: average GPS contacts sharing that hop.
-            // For a round-trip path (flipPathRound), the target-side hop sits
-            // in the middle of the symmetric sequence; .last is the local side.
-            final lastHop = (widget.flipPathRound && pathData.length > 1)
-                ? pathData[(pathData.length - 1) ~/ 2]
-                : pathData.last;
-            final peers = connector.contacts
+            // For a round-trip path (flipPathAround/reversePathAround), the target-side hop
+            // sits in the middle of the symmetric sequence; .last is the local side.
+            final lastHop = widget.reversePathAround
+                ? widget.path.first
+                : widget.path.last;
+
+            final peers = connector.allContacts
                 .where(
                   (c) =>
                       c.hasLocation &&
@@ -339,12 +335,34 @@ class _PathTraceMapScreenState extends State<PathTraceMapScreen> {
                   peers.map((c) => c.longitude!).reduce((a, b) => a + b) /
                   peers.length;
               const offsetDeg = 0.003;
-              final angle = (target.publicKey[1] / 255.0) * 2 * pi;
+              final angle = (tc.publicKey[1] / 255.0) * 2 * pi;
               targetPos = LatLng(
                 lat + offsetDeg * cos(angle),
                 lon + offsetDeg * sin(angle),
               );
               targetGuessed = true;
+            } else if (inferredPositions.containsKey(lastHop)) {
+              final lat = inferredPositions[lastHop]!.latitude;
+              final lon = inferredPositions[lastHop]!.longitude;
+              const offsetDeg = 0.003;
+              final angle = (tc.publicKey[1] / 255.0) * 2 * pi;
+              targetPos = LatLng(
+                lat + offsetDeg * cos(angle),
+                lon + offsetDeg * sin(angle),
+              );
+              targetGuessed = true;
+            } else {
+              // As a last resort, just place it at the same position as the last hop.
+              final contact = pathContacts[lastHop];
+              if (contact != null && contact.hasLocation) {
+                const offsetDeg = 0.003;
+                final angle = (tc.publicKey[1] / 255.0) * 2 * pi;
+                targetPos = LatLng(
+                  contact.latitude! + offsetDeg * cos(angle),
+                  contact.longitude! + offsetDeg * sin(angle),
+                );
+                targetGuessed = true;
+              }
             }
           }
         }
@@ -353,7 +371,12 @@ class _PathTraceMapScreenState extends State<PathTraceMapScreen> {
 
         _points = <LatLng>[];
         _points.add(LatLng(connector.selfLatitude!, connector.selfLongitude!));
+        int hopLast = 0;
+        int hopLastLast = 0;
         for (final hop in _traceData!.pathData) {
+          if (hop == hopLastLast && widget.flipPathAround) {
+            break; //skip duplicate hops in round-trip paths
+          }
           final contact = _traceData!.pathContacts[hop];
           if (contact != null && contact.hasLocation) {
             _points.add(LatLng(contact.latitude!, contact.longitude!));
@@ -361,8 +384,14 @@ class _PathTraceMapScreenState extends State<PathTraceMapScreen> {
             final inferred = inferredPositions[hop];
             if (inferred != null) _points.add(inferred);
           }
+          hopLastLast = hopLast;
+          hopLast = hop;
+        }
+        if (targetPos != null) {
+          if (_targetContact != null && _targetContact!.type == advTypeChat) {
+            _points.add(targetPos);
+          }
         }
-        if (targetPos != null) _points.add(targetPos);
         _polylines = _points.length > 1
             ? [
                 Polyline(
@@ -451,7 +480,8 @@ class _PathTraceMapScreenState extends State<PathTraceMapScreen> {
                       ],
                     ),
                   ),
-                if (_hasData) _buildMapPathTrace(context, tileCache),
+                if (_hasData)
+                  _buildMapPathTrace(context, tileCache, _targetContact),
                 if (_points.isEmpty &&
                     !_hasData &&
                     !_isLoading &&
@@ -480,17 +510,28 @@ class _PathTraceMapScreenState extends State<PathTraceMapScreen> {
   List<Marker> _buildHopMarkers(
     List<int> pathData, {
     required bool showLabels,
+    required Contact? target,
   }) {
     final markers = <Marker>[];
+    int hopLast = 0;
+    int hopLastLast = 0;
     for (final hop in pathData) {
       final contact = _traceData!.pathContacts[hop];
       final inferred = _inferredHopPositions[hop];
       final hasGps = contact != null && contact.hasLocation;
-      if (!hasGps && inferred == null) continue;
+      if (hop == hopLastLast && widget.flipPathAround) {
+        continue; //skip duplicate hops in round-trip paths
+      }
+      if (!hasGps && inferred == null) {
+        hopLastLast = hopLast;
+        hopLast = hop;
+        continue; //skip hops with no GPS and no inferred position
+      }
       final point = hasGps
           ? LatLng(contact.latitude!, contact.longitude!)
           : inferred!;
       final label = hop.toRadixString(16).padLeft(2, '0').toUpperCase();
+
       markers.add(
         Marker(
           point: point,
@@ -532,6 +573,8 @@ class _PathTraceMapScreenState extends State<PathTraceMapScreen> {
           ),
         );
       }
+      hopLastLast = hopLast;
+      hopLast = hop;
     }
 
     final selfLat = context.read<MeshCoreConnector>().selfLatitude;
@@ -581,9 +624,9 @@ class _PathTraceMapScreenState extends State<PathTraceMapScreen> {
 
     // Add target contact endpoint marker.
     final targetPos = _targetContactPosition;
-    if (targetPos != null) {
+    if (targetPos != null && target != null && target.type == advTypeChat) {
       final isGuessed = _targetContactIsGuessed;
-      final targetName = widget.targetContact?.name ?? '?';
+      final targetName = target.name;
       markers.add(
         Marker(
           point: targetPos,
@@ -719,6 +762,7 @@ class _PathTraceMapScreenState extends State<PathTraceMapScreen> {
   Widget _buildMapPathTrace(
     BuildContext context,
     MapTileCacheService tileCache,
+    Contact? target,
   ) {
     return FlutterMap(
       key: _mapKey,
@@ -757,6 +801,7 @@ class _PathTraceMapScreenState extends State<PathTraceMapScreen> {
             markers: _buildHopMarkers(
               _traceData!.pathData,
               showLabels: _showNodeLabels,
+              target: target,
             ),
           ),
       ],

lib/screens/tcp_screen.dart

@@ -5,6 +5,7 @@ import 'package:provider/provider.dart';
 
 import '../connector/meshcore_connector.dart';
 import '../l10n/l10n.dart';
+import '../services/app_settings_service.dart';
 import '../utils/platform_info.dart';
 import '../widgets/adaptive_app_bar_title.dart';
 import 'contacts_screen.dart';
@@ -27,8 +28,14 @@ class _TcpScreenState extends State<TcpScreen> {
   @override
   void initState() {
     super.initState();
-    _hostController = TextEditingController();
-    _portController = TextEditingController(text: '5000');
+    _hostController = TextEditingController(
+      text: context.read<AppSettingsService>().settings.tcpServerAddress,
+    );
+    _portController = TextEditingController(
+      text: context.read<AppSettingsService>().settings.tcpServerPort > 0
+          ? context.read<AppSettingsService>().settings.tcpServerPort.toString()
+          : '',
+    );
     _connector = context.read<MeshCoreConnector>();
 
     _connectionListener = () {
@@ -39,6 +46,12 @@ class _TcpScreenState extends State<TcpScreen> {
       if (_connector.state == MeshCoreConnectionState.connected &&
           _connector.isTcpTransportConnected &&
           !_navigatedToContacts) {
+        context.read<AppSettingsService>().setTcpServerAddress(
+          _hostController.text,
+        );
+        context.read<AppSettingsService>().setTcpServerPort(
+          int.tryParse(_portController.text) ?? 0,
+        );
         _navigatedToContacts = true;
         Navigator.of(context).pushReplacement(
           MaterialPageRoute(builder: (_) => const ContactsScreen()),

lib/services/app_debug_log_service.dart

@@ -51,6 +51,7 @@ class AppDebugLogService extends ChangeNotifier {
     String message, {
     String tag = 'App',
     AppDebugLogLevel level = AppDebugLogLevel.info,
+    bool noNotify = false,
   }) {
     if (!_enabled && !kDebugMode) return;
     if (!_enabled) {
@@ -72,22 +73,24 @@ class AppDebugLogService extends ChangeNotifier {
       _entries.removeRange(0, _entries.length - maxEntries);
     }
 
-    notifyListeners();
+    if (!noNotify) {
+      notifyListeners();
+    }
 
     // Also print to console for development
     debugPrint('[$tag] $message');
   }
 
-  void info(String message, {String tag = 'App'}) {
-    log(message, tag: tag, level: AppDebugLogLevel.info);
+  void info(String message, {String tag = 'App', bool noNotify = false}) {
+    log(message, tag: tag, level: AppDebugLogLevel.info, noNotify: noNotify);
   }
 
-  void warn(String message, {String tag = 'App'}) {
-    log(message, tag: tag, level: AppDebugLogLevel.warning);
+  void warn(String message, {String tag = 'App', bool noNotify = false}) {
+    log(message, tag: tag, level: AppDebugLogLevel.warning, noNotify: noNotify);
   }
 
-  void error(String message, {String tag = 'App'}) {
-    log(message, tag: tag, level: AppDebugLogLevel.error);
+  void error(String message, {String tag = 'App', bool noNotify = false}) {
+    log(message, tag: tag, level: AppDebugLogLevel.error, noNotify: noNotify);
   }
 
   void clear() {

lib/services/app_settings_service.dart

@@ -182,4 +182,12 @@ class AppSettingsService extends ChangeNotifier {
       ..remove(channelName);
     await updateSettings(_settings.copyWith(mutedChannels: updated));
   }
+
+  Future<void> setTcpServerAddress(String value) async {
+    await updateSettings(_settings.copyWith(tcpServerAddress: value));
+  }
+
+  Future<void> setTcpServerPort(int value) async {
+    await updateSettings(_settings.copyWith(tcpServerPort: value));
+  }
 }

lib/services/chat_text_scale_service.dart

@@ -65,7 +65,7 @@ class ChatTextScaleService extends ChangeNotifier {
 
   void _commitScale() {
     _saveTimer?.cancel();
-    PrefsManager.instance.setDouble(_prefKey, _scale);
+    unawaited(PrefsManager.instance.setDouble(_prefKey, _scale));
   }
 
   double _clamp(double value) => value.clamp(_minScale, _maxScale).toDouble();

lib/services/message_retry_service.dart

@@ -58,12 +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();
 
@@ -73,12 +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;
@@ -91,6 +100,7 @@ class MessageRetryService extends ChangeNotifier {
     _appSettingsService = appSettingsService;
     _debugLogService = debugLogService;
     _recordPathResultCallback = recordPathResultCallback;
+    _onDeliveryObservedCallback = onDeliveryObservedCallback;
   }
 
   /// Compute expected ACK hash using same algorithm as firmware:
@@ -423,25 +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) {
-      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;
-      }
-      actualTimeout = _calculateTimeoutCallback!(
+    if (_calculateTimeoutCallback != null) {
+      final calculated = _calculateTimeoutCallback!(
         pathLengthValue,
         message.text.length,
+        contactKey: contact.publicKeyHex,
       );
-      debugPrint(
-        'Using calculated timeout: ${actualTimeout}ms for path length $pathLengthValue',
-      );
+      // calculateTimeout tries ML first, falls back to physics.
+      // 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(
@@ -738,6 +756,16 @@ 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);
       }
 

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());
+    }
+  }
+}

lib/services/ui_view_state_service.dart

@@ -0,0 +1,154 @@
+import 'dart:async';
+
+import 'package:flutter/foundation.dart';
+
+import '../storage/prefs_manager.dart';
+import '../utils/contact_search.dart';
+
+const String contactsAllGroupsValue = '__all__';
+
+enum ChannelSortOption { manual, name, latestMessages, unread }
+
+class UiViewStateService extends ChangeNotifier {
+  static const _keyContactsSelectedGroupName = 'ui_contacts_selected_group';
+  static const _keyContactsSortOption = 'ui_contacts_sort_option';
+  static const _keyContactsShowUnreadOnly = 'ui_contacts_show_unread_only';
+  static const _keyContactsTypeFilter = 'ui_contacts_type_filter';
+  static const _keyChannelsSortOption = 'ui_channels_sort_option';
+  static const _keyChannelsSortIndexLegacy = 'ui_channels_sort_index';
+
+  String _contactsSelectedGroupName = contactsAllGroupsValue;
+  String _contactsSearchText = '';
+  bool _contactsSearchExpanded = false;
+  ContactSortOption _contactsSortOption = ContactSortOption.lastSeen;
+  bool _contactsShowUnreadOnly = false;
+  ContactTypeFilter _contactsTypeFilter = ContactTypeFilter.all;
+
+  String _channelsSearchText = '';
+  ChannelSortOption _channelsSortOption = ChannelSortOption.manual;
+
+  String get contactsSelectedGroupName => _contactsSelectedGroupName;
+  String get contactsSearchText => _contactsSearchText;
+  bool get contactsSearchExpanded => _contactsSearchExpanded;
+  ContactSortOption get contactsSortOption => _contactsSortOption;
+  bool get contactsShowUnreadOnly => _contactsShowUnreadOnly;
+  ContactTypeFilter get contactsTypeFilter => _contactsTypeFilter;
+  String get channelsSearchText => _channelsSearchText;
+  ChannelSortOption get channelsSortOption => _channelsSortOption;
+
+  Future<void> initialize() async {
+    final prefs = PrefsManager.instance;
+
+    final selectedGroupName = prefs.getString(_keyContactsSelectedGroupName);
+    if (selectedGroupName != null && selectedGroupName.isNotEmpty) {
+      _contactsSelectedGroupName = selectedGroupName;
+    }
+
+    final sortStr = prefs.getString(_keyContactsSortOption);
+    if (sortStr != null) {
+      _contactsSortOption = ContactSortOption.values.firstWhere(
+        (e) => e.name == sortStr,
+        orElse: () => ContactSortOption.lastSeen,
+      );
+    }
+
+    _contactsShowUnreadOnly =
+        prefs.getBool(_keyContactsShowUnreadOnly) ?? false;
+
+    final typeStr = prefs.getString(_keyContactsTypeFilter);
+    if (typeStr != null) {
+      _contactsTypeFilter = ContactTypeFilter.values.firstWhere(
+        (e) => e.name == typeStr,
+        orElse: () => ContactTypeFilter.all,
+      );
+    }
+
+    final channelSortStr = prefs.getString(_keyChannelsSortOption);
+    if (channelSortStr != null) {
+      _channelsSortOption = ChannelSortOption.values.firstWhere(
+        (e) => e.name == channelSortStr,
+        orElse: () => ChannelSortOption.manual,
+      );
+      return;
+    }
+
+    // Backward compatibility for old persisted index format.
+    switch (prefs.getInt(_keyChannelsSortIndexLegacy) ?? 0) {
+      case 0:
+        _channelsSortOption = ChannelSortOption.manual;
+        break;
+      case 1:
+        _channelsSortOption = ChannelSortOption.name;
+        break;
+      case 2:
+        _channelsSortOption = ChannelSortOption.latestMessages;
+        break;
+      case 3:
+        _channelsSortOption = ChannelSortOption.unread;
+        break;
+      default:
+        _channelsSortOption = ChannelSortOption.manual;
+    }
+  }
+
+  void setContactsSelectedGroupName(String value) {
+    if (_contactsSelectedGroupName == value) return;
+    _contactsSelectedGroupName = value;
+    notifyListeners();
+    unawaited(
+      PrefsManager.instance.setString(_keyContactsSelectedGroupName, value),
+    );
+  }
+
+  void setContactsSearchText(String value) {
+    if (_contactsSearchText == value) return;
+    _contactsSearchText = value;
+    notifyListeners();
+  }
+
+  void setContactsSearchExpanded(bool value) {
+    if (_contactsSearchExpanded == value) return;
+    _contactsSearchExpanded = value;
+    notifyListeners();
+  }
+
+  void setContactsSortOption(ContactSortOption value) {
+    if (_contactsSortOption == value) return;
+    _contactsSortOption = value;
+    notifyListeners();
+    unawaited(
+      PrefsManager.instance.setString(_keyContactsSortOption, value.name),
+    );
+  }
+
+  void setContactsShowUnreadOnly(bool value) {
+    if (_contactsShowUnreadOnly == value) return;
+    _contactsShowUnreadOnly = value;
+    notifyListeners();
+    unawaited(PrefsManager.instance.setBool(_keyContactsShowUnreadOnly, value));
+  }
+
+  void setContactsTypeFilter(ContactTypeFilter value) {
+    if (_contactsTypeFilter == value) return;
+    _contactsTypeFilter = value;
+    notifyListeners();
+    unawaited(
+      PrefsManager.instance.setString(_keyContactsTypeFilter, value.name),
+    );
+  }
+
+  void setChannelsSearchText(String value) {
+    if (_channelsSearchText == value) return;
+    _channelsSearchText = value;
+    notifyListeners();
+  }
+
+  void setChannelsSortOption(ChannelSortOption value) {
+    if (_channelsSortOption == value) return;
+    _channelsSortOption = value;
+    notifyListeners();
+    unawaited(
+      PrefsManager.instance.setString(_keyChannelsSortOption, value.name),
+    );
+  }
+}

lib/services/usb_serial_service_native.dart

@@ -189,6 +189,10 @@ class UsbSerialService {
           serial.setStopBits1();
           serial.setFlowControlNone();
           serial.setRTS(false);
+          // Toggle DTR low→high so the device sees a fresh connection even
+          // if the previous disconnect didn't cleanly signal DTR drop.
+          serial.setDTR(false);
+          await Future<void>.delayed(const Duration(milliseconds: 50));
           serial.setDTR(true);
           _serial = serial;
           // Update the normalized port name to whichever candidate succeeded.
@@ -249,6 +253,21 @@ class UsbSerialService {
     _status = UsbSerialStatus.connected;
   }
 
+  Future<void> writeRaw(Uint8List data) async {
+    if (!isConnected) {
+      throw StateError('USB serial port is not open');
+    }
+    if (_useAndroidUsbHost) {
+      try {
+        await _androidMethodChannel.invokeMethod<void>('write', {'data': data});
+      } on PlatformException catch (error) {
+        throw StateError(error.message ?? error.code);
+      }
+    } else {
+      _serial!.write(data);
+    }
+  }
+
   Future<void> write(Uint8List data) async {
     if (!isConnected) {
       throw StateError('USB serial port is not open');
@@ -300,6 +319,7 @@ class UsbSerialService {
       _serial = null;
       try {
         if (serial?.isOpen() == FlOpenStatus.open) {
+          serial?.setDTR(false);
           serial?.closePort();
         }
       } catch (_) {
@@ -350,6 +370,7 @@ class UsbSerialService {
       final serial = _serial;
       try {
         if (serial?.isOpen() == FlOpenStatus.open) {
+          serial?.setDTR(false);
           serial?.closePort(); // synchronous C call — kills the SerialThread
         }
       } catch (_) {}

lib/services/usb_serial_service_web.dart

@@ -127,6 +127,17 @@ class UsbSerialService {
     }
   }
 
+  Future<void> writeRaw(Uint8List data) async {
+    if (!isConnected || _writer == null) {
+      throw StateError('USB serial port is not open');
+    }
+    final promise = _writer!.callMethod<JSPromise<JSAny?>>(
+      'write'.toJS,
+      data.toJS,
+    );
+    await promise.toDart;
+  }
+
   Future<void> write(Uint8List data) async {
     if (!isConnected || _writer == null) {
       throw StateError('USB serial port is not open');

lib/utils/app_logger.dart

@@ -23,23 +23,23 @@ class AppLogger {
   bool get isEnabled => _enabled;
 
   /// Log an info message
-  void info(String message, {String tag = 'App'}) {
+  void info(String message, {String tag = 'App', bool noNotify = false}) {
     if (_enabled && _service != null) {
-      _service!.info(message, tag: tag);
+      _service!.info(message, tag: tag, noNotify: noNotify);
     }
   }
 
   /// Log a warning message
-  void warn(String message, {String tag = 'App'}) {
+  void warn(String message, {String tag = 'App', bool noNotify = false}) {
     if (_enabled && _service != null) {
-      _service!.warn(message, tag: tag);
+      _service!.warn(message, tag: tag, noNotify: noNotify);
     }
   }
 
   /// Log an error message
-  void error(String message, {String tag = 'App'}) {
+  void error(String message, {String tag = 'App', bool noNotify = false}) {
     if (_enabled && _service != null) {
-      _service!.error(message, tag: tag);
+      _service!.error(message, tag: tag, noNotify: noNotify);
     }
   }
 
@@ -48,9 +48,10 @@ class AppLogger {
     String message, {
     String tag = 'App',
     AppDebugLogLevel level = AppDebugLogLevel.info,
+    bool noNotify = false,
   }) {
     if (_enabled && _service != null) {
-      _service!.log(message, tag: tag, level: level);
+      _service!.log(message, tag: tag, level: level, noNotify: noNotify);
     }
   }
 }

lib/utils/contact_filter_types.dart

@@ -0,0 +1,3 @@
+enum ContactSortOption { lastSeen, recentMessages, name }
+
+enum ContactTypeFilter { all, favorites, users, repeaters, rooms }

lib/utils/contact_search.dart

@@ -1,5 +1,7 @@
 import '../models/contact.dart';
 
+export 'contact_filter_types.dart';
+
 bool matchesContactQuery(Contact contact, String query) {
   final normalizedQuery = query.trim().toLowerCase();
   if (normalizedQuery.isEmpty) return true;

lib/widgets/list_filter_widget.dart

@@ -1,12 +1,9 @@
 import 'package:flutter/material.dart';
 import '../l10n/l10n.dart';
+import '../utils/contact_search.dart';
 
-enum ContactSortOption { lastSeen, recentMessages, name }
-
-enum ContactTypeFilter { all, favorites, users, repeaters, rooms }
-
-class SortFilterMenuOption {
-  final int value;
+class SortFilterMenuOption<T> {
+  final T value;
   final String label;
   final bool? checked;
 
@@ -17,16 +14,16 @@ class SortFilterMenuOption {
   });
 }
 
-class SortFilterMenuSection {
+class SortFilterMenuSection<T> {
   final String title;
-  final List<SortFilterMenuOption> options;
+  final List<SortFilterMenuOption<T>> options;
 
   const SortFilterMenuSection({required this.title, required this.options});
 }
 
-class SortFilterMenu extends StatelessWidget {
-  final List<SortFilterMenuSection> sections;
-  final ValueChanged<int> onSelected;
+class SortFilterMenu<T> extends StatelessWidget {
+  final List<SortFilterMenuSection<T>> sections;
+  final ValueChanged<T> onSelected;
   final String tooltip;
   final Widget icon;
 
@@ -40,7 +37,7 @@ class SortFilterMenu extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    return PopupMenuButton<int>(
+    return PopupMenuButton<T>(
       icon: icon,
       tooltip: tooltip,
       onSelected: onSelected,
@@ -53,11 +50,11 @@ class SortFilterMenu extends StatelessWidget {
         final visibleSections = sections
             .where((section) => section.options.isNotEmpty)
             .toList();
-        final entries = <PopupMenuEntry<int>>[];
+        final entries = <PopupMenuEntry<T>>[];
         for (int i = 0; i < visibleSections.length; i++) {
           final section = visibleSections[i];
           entries.add(
-            PopupMenuItem<int>(
+            PopupMenuItem<T>(
               enabled: false,
               child: Text(section.title, style: labelStyle),
             ),
@@ -65,14 +62,14 @@ class SortFilterMenu extends StatelessWidget {
           for (final option in section.options) {
             if (option.checked == null) {
               entries.add(
-                PopupMenuItem<int>(
+                PopupMenuItem<T>(
                   value: option.value,
                   child: Text(option.label),
                 ),
               );
             } else {
               entries.add(
-                CheckedPopupMenuItem<int>(
+                CheckedPopupMenuItem<T>(
                   value: option.value,
                   checked: option.checked ?? false,
                   child: Text(option.label),
@@ -90,16 +87,23 @@ class SortFilterMenu extends StatelessWidget {
   }
 }
 
-const int _actionSortRecentMessages = 1;
-const int _actionSortName = 2;
-const int _actionSortLastSeen = 3;
-const int _actionFilterAll = 4;
-const int _actionFilterFavorites = 5;
-const int _actionFilterUsers = 6;
-const int _actionFilterRepeaters = 7;
-const int _actionFilterRooms = 8;
-const int _actionToggleUnreadOnly = 9;
-const int _actionNewGroup = 10;
+sealed class _ContactsFilterAction {
+  const _ContactsFilterAction();
+}
+
+class _SortAction extends _ContactsFilterAction {
+  final ContactSortOption option;
+  const _SortAction(this.option);
+}
+
+class _TypeFilterAction extends _ContactsFilterAction {
+  final ContactTypeFilter filter;
+  const _TypeFilterAction(this.filter);
+}
+
+class _ToggleUnreadAction extends _ContactsFilterAction {
+  const _ToggleUnreadAction();
+}
 
 class ContactsFilterMenu extends StatelessWidget {
   final ContactSortOption sortOption;
@@ -108,7 +112,6 @@ class ContactsFilterMenu extends StatelessWidget {
   final ValueChanged<ContactSortOption> onSortChanged;
   final ValueChanged<ContactTypeFilter> onTypeFilterChanged;
   final ValueChanged<bool> onUnreadOnlyChanged;
-  final VoidCallback onNewGroup;
 
   const ContactsFilterMenu({
     super.key,
@@ -118,30 +121,29 @@ class ContactsFilterMenu extends StatelessWidget {
     required this.onSortChanged,
     required this.onTypeFilterChanged,
     required this.onUnreadOnlyChanged,
-    required this.onNewGroup,
   });
 
   @override
   Widget build(BuildContext context) {
     final l10n = context.l10n;
-    return SortFilterMenu(
+    return SortFilterMenu<_ContactsFilterAction>(
       tooltip: l10n.listFilter_tooltip,
       sections: [
         SortFilterMenuSection(
           title: l10n.listFilter_sortBy,
           options: [
             SortFilterMenuOption(
-              value: _actionSortRecentMessages,
+              value: _SortAction(ContactSortOption.recentMessages),
               label: l10n.listFilter_latestMessages,
               checked: sortOption == ContactSortOption.recentMessages,
             ),
             SortFilterMenuOption(
-              value: _actionSortLastSeen,
+              value: _SortAction(ContactSortOption.lastSeen),
               label: l10n.listFilter_heardRecently,
               checked: sortOption == ContactSortOption.lastSeen,
             ),
             SortFilterMenuOption(
-              value: _actionSortName,
+              value: _SortAction(ContactSortOption.name),
               label: l10n.listFilter_az,
               checked: sortOption == ContactSortOption.name,
             ),
@@ -151,80 +153,66 @@ class ContactsFilterMenu extends StatelessWidget {
           title: l10n.listFilter_filters,
           options: [
             SortFilterMenuOption(
-              value: _actionFilterAll,
+              value: _TypeFilterAction(ContactTypeFilter.all),
               label: l10n.listFilter_all,
               checked: typeFilter == ContactTypeFilter.all,
             ),
             SortFilterMenuOption(
-              value: _actionFilterFavorites,
+              value: _TypeFilterAction(ContactTypeFilter.favorites),
               label: l10n.listFilter_favorites,
               checked: typeFilter == ContactTypeFilter.favorites,
             ),
             SortFilterMenuOption(
-              value: _actionFilterUsers,
+              value: _TypeFilterAction(ContactTypeFilter.users),
               label: l10n.listFilter_users,
               checked: typeFilter == ContactTypeFilter.users,
             ),
             SortFilterMenuOption(
-              value: _actionFilterRepeaters,
+              value: _TypeFilterAction(ContactTypeFilter.repeaters),
               label: l10n.listFilter_repeaters,
               checked: typeFilter == ContactTypeFilter.repeaters,
             ),
             SortFilterMenuOption(
-              value: _actionFilterRooms,
+              value: _TypeFilterAction(ContactTypeFilter.rooms),
               label: l10n.listFilter_roomServers,
               checked: typeFilter == ContactTypeFilter.rooms,
             ),
             SortFilterMenuOption(
-              value: _actionToggleUnreadOnly,
+              value: const _ToggleUnreadAction(),
               label: l10n.listFilter_unreadOnly,
               checked: showUnreadOnly,
             ),
-            SortFilterMenuOption(
-              value: _actionNewGroup,
-              label: l10n.listFilter_newGroup,
-            ),
           ],
         ),
       ],
       onSelected: (action) {
         switch (action) {
-          case _actionSortRecentMessages:
-            onSortChanged(ContactSortOption.recentMessages);
-            break;
-          case _actionSortName:
-            onSortChanged(ContactSortOption.name);
-            break;
-          case _actionSortLastSeen:
-            onSortChanged(ContactSortOption.lastSeen);
-            break;
-          case _actionFilterAll:
-            onTypeFilterChanged(ContactTypeFilter.all);
-            break;
-          case _actionFilterUsers:
-            onTypeFilterChanged(ContactTypeFilter.users);
-            break;
-          case _actionFilterFavorites:
-            onTypeFilterChanged(ContactTypeFilter.favorites);
-            break;
-          case _actionFilterRepeaters:
-            onTypeFilterChanged(ContactTypeFilter.repeaters);
-            break;
-          case _actionFilterRooms:
-            onTypeFilterChanged(ContactTypeFilter.rooms);
-            break;
-          case _actionToggleUnreadOnly:
+          case _SortAction(:final option):
+            onSortChanged(option);
+          case _TypeFilterAction(:final filter):
+            onTypeFilterChanged(filter);
+          case _ToggleUnreadAction():
             onUnreadOnlyChanged(!showUnreadOnly);
-            break;
-          case _actionNewGroup:
-            onNewGroup();
-            break;
         }
       },
     );
   }
 }
 
+sealed class _DiscoveryFilterAction {
+  const _DiscoveryFilterAction();
+}
+
+class _DiscoverySortAction extends _DiscoveryFilterAction {
+  final ContactSortOption option;
+  const _DiscoverySortAction(this.option);
+}
+
+class _DiscoveryTypeFilterAction extends _DiscoveryFilterAction {
+  final ContactTypeFilter filter;
+  const _DiscoveryTypeFilterAction(this.filter);
+}
+
 class DiscoveryContactsFilterMenu extends StatelessWidget {
   final ContactSortOption sortOption;
   final ContactTypeFilter typeFilter;
@@ -242,19 +230,19 @@ class DiscoveryContactsFilterMenu extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     final l10n = context.l10n;
-    return SortFilterMenu(
+    return SortFilterMenu<_DiscoveryFilterAction>(
       tooltip: l10n.listFilter_tooltip,
       sections: [
         SortFilterMenuSection(
           title: l10n.listFilter_sortBy,
           options: [
             SortFilterMenuOption(
-              value: _actionSortLastSeen,
+              value: _DiscoverySortAction(ContactSortOption.lastSeen),
               label: l10n.listFilter_heardRecently,
               checked: sortOption == ContactSortOption.lastSeen,
             ),
             SortFilterMenuOption(
-              value: _actionSortName,
+              value: _DiscoverySortAction(ContactSortOption.name),
               label: l10n.listFilter_az,
               checked: sortOption == ContactSortOption.name,
             ),
@@ -264,22 +252,22 @@ class DiscoveryContactsFilterMenu extends StatelessWidget {
           title: l10n.listFilter_filters,
           options: [
             SortFilterMenuOption(
-              value: _actionFilterAll,
+              value: _DiscoveryTypeFilterAction(ContactTypeFilter.all),
               label: l10n.listFilter_all,
               checked: typeFilter == ContactTypeFilter.all,
             ),
             SortFilterMenuOption(
-              value: _actionFilterUsers,
+              value: _DiscoveryTypeFilterAction(ContactTypeFilter.users),
               label: l10n.listFilter_users,
               checked: typeFilter == ContactTypeFilter.users,
             ),
             SortFilterMenuOption(
-              value: _actionFilterRepeaters,
+              value: _DiscoveryTypeFilterAction(ContactTypeFilter.repeaters),
               label: l10n.listFilter_repeaters,
               checked: typeFilter == ContactTypeFilter.repeaters,
             ),
             SortFilterMenuOption(
-              value: _actionFilterRooms,
+              value: _DiscoveryTypeFilterAction(ContactTypeFilter.rooms),
               label: l10n.listFilter_roomServers,
               checked: typeFilter == ContactTypeFilter.rooms,
             ),
@@ -288,27 +276,10 @@ class DiscoveryContactsFilterMenu extends StatelessWidget {
       ],
       onSelected: (action) {
         switch (action) {
-          case _actionSortName:
-            onSortChanged(ContactSortOption.name);
-            break;
-          case _actionSortLastSeen:
-            onSortChanged(ContactSortOption.lastSeen);
-            break;
-          case _actionFilterAll:
-            onTypeFilterChanged(ContactTypeFilter.all);
-            break;
-          case _actionFilterUsers:
-            onTypeFilterChanged(ContactTypeFilter.users);
-            break;
-          case _actionFilterFavorites:
-            onTypeFilterChanged(ContactTypeFilter.favorites);
-            break;
-          case _actionFilterRepeaters:
-            onTypeFilterChanged(ContactTypeFilter.repeaters);
-            break;
-          case _actionFilterRooms:
-            onTypeFilterChanged(ContactTypeFilter.rooms);
-            break;
+          case _DiscoverySortAction(:final option):
+            onSortChanged(option);
+          case _DiscoveryTypeFilterAction(:final filter):
+            onTypeFilterChanged(filter);
         }
       },
     );

lib/widgets/path_management_dialog.dart

@@ -78,7 +78,7 @@ class _PathManagementDialogState extends State<_PathManagementDialog> {
                 builder: (context) => PathTraceMapScreen(
                   title: context.l10n.contacts_repeaterPathTrace,
                   path: Uint8List.fromList(pathBytes),
-                  flipPathRound: true,
+                  flipPathAround: true,
                   targetContact: widget.contact,
                 ),
               ),
@@ -107,7 +107,7 @@ class _PathManagementDialogState extends State<_PathManagementDialog> {
     }
 
     final pathForInput = currentContact.pathIdList;
-    final availableContacts = connector.contacts
+    final availableContacts = connector.allContacts
         .where((c) => c.publicKeyHex != currentContact.publicKeyHex)
         .toList();
 

lib/widgets/path_selection_dialog.dart

@@ -1,5 +1,6 @@
 import 'dart:typed_data';
 import 'package:flutter/material.dart';
+import 'package:meshcore_open/connector/meshcore_protocol.dart';
 import '../l10n/l10n.dart';
 import '../models/contact.dart';
 
@@ -65,7 +66,7 @@ class _PathSelectionDialogState extends State<PathSelectionDialog> {
 
   void _filterValidContacts() {
     _validContacts = widget.availableContacts
-        .where((c) => c.type == 2 || c.type == 3)
+        .where((c) => c.type == advTypeRepeater || c.type == advTypeRoom)
         .toList();
   }
 

lib/widgets/snr_indicator.dart

@@ -157,10 +157,7 @@ class _SNRIndicatorState extends State<SNRIndicator> {
                   repeater.snr,
                   widget.connector.currentSf,
                 );
-                final allContacts = [
-                  ...widget.connector.contacts,
-                  ...widget.connector.discoveredContacts,
-                ];
+                final allContacts = widget.connector.allContacts;
                 final name = allContacts
                     .where((c) => c.publicKey.first == repeater.pubkeyFirstByte)
                     .map((c) => c.name)

pubspec.yaml

@@ -16,7 +16,7 @@ publish_to: 'none' # Remove this line if you wish to publish to pub.dev
 # https://developer.apple.com/library/archive/documentation/General/Reference/InfoPlistKeyReference/Articles/CoreFoundationKeys.html
 # In Windows, build-name is used as the major, minor, and patch parts
 # of the product and file versions while build-number is used as the build suffix.
-version: 6.0.0+7
+version: 7.0.0+8
 
 environment:
   sdk: ^3.9.2
@@ -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(),
+  );
+}