fix: Align contact sorting labels #0

lib/models/channel.dart

@@ -57,9 +57,7 @@ class Channel {
     } else {
       // Normal channel: require explicit secret
       if (explicitSecret == null || explicitSecret.length != 16) {
-        throw ArgumentError(
-          'Normal channels require a 16-byte secret',
-        );
+        throw ArgumentError('Normal channels require a 16-byte secret');
       }
       return Channel(
         index: index,
@@ -78,6 +76,18 @@ class Channel {
     return Uint8List.fromList(digest.bytes.sublist(0, 16));
   }
 
+  static bool isHashChannelName(String channelName) {
+    return channelName.trim().startsWith('#');
+  }
+
+  static String pskBase64ForHashChannelName(String channelName) {
+    final normalized = channelName.trim();
+    if (!isHashChannelName(normalized)) {
+      throw ArgumentError('Only #channels can export derived psk_base64');
+    }
+    return base64.encode(_generateHashChannelSecret(normalized));
+  }
+
   /// Create the default public channel (channel 0)
   /// Uses the well-known pre-shared key from MeshCore
   factory Channel.publicChannel() {
@@ -85,8 +95,22 @@ class Channel {
       index: 0,
       name: 'Public Channel',
       secret: Uint8List.fromList([
-        0x8b, 0x33, 0x87, 0xe9, 0xc5, 0xcd, 0xea, 0x6a,
-        0xc9, 0xe5, 0xed, 0xba, 0xa1, 0x15, 0xcd, 0x72,
+        0x8b,
+        0x33,
+        0x87,
+        0xe9,
+        0xc5,
+        0xcd,
+        0xea,
+        0x6a,
+        0xc9,
+        0xe5,
+        0xed,
+        0xba,
+        0xa1,
+        0x15,
+        0xcd,
+        0x72,
       ]),
       flags: null,
     );
@@ -95,6 +119,9 @@ class Channel {
   /// Check if this is a hash-based channel (name starts with '#')
   bool get isHashChannel => name.startsWith('#');
 
+  /// Base64-encoded PSK for sharing with firmware CLI and related tooling.
+  String get pskBase64 => base64.encode(secret);
+
   /// Display name for the channel
   /// Returns "Public" for channel 0, otherwise returns the custom name or "Channel N"
   String get displayName {
@@ -131,12 +158,7 @@ class Channel {
   }
 
   /// Create a copy with modified fields
-  Channel copyWith({
-    int? index,
-    String? name,
-    Uint8List? secret,
-    int? flags,
-  }) {
+  Channel copyWith({int? index, String? name, Uint8List? secret, int? flags}) {
     return Channel(
       index: index ?? this.index,
       name: name ?? this.name,

lib/providers/app_provider.dart

@@ -107,6 +107,15 @@ class _PendingRepeaterOwnerRequest {
   const _PendingRepeaterOwnerRequest({required this.publicKey});
 }
 
+enum ContactsTabSection {
+  favourites,
+  teamMembers,
+  repeaters,
+  sensors,
+  rooms,
+  channels,
+}
+
 /// Main App Provider - coordinates all other providers
 class AppProvider with ChangeNotifier {
   static const int _maxDirectPayloadHops = 3;
@@ -162,6 +171,9 @@ class AppProvider with ChangeNotifier {
   bool get isContactsEnabled => _isContactsEnabled;
   bool _isSensorsEnabled = true;
   bool get isSensorsEnabled => _isSensorsEnabled;
+  final Map<ContactsTabSection, bool> _contactsSectionVisibility = {
+    for (final section in ContactsTabSection.values) section: true,
+  };
 
   bool _isVoiceSilenceTrimmingEnabled = true;
   bool get isVoiceSilenceTrimmingEnabled => _isVoiceSilenceTrimmingEnabled;
@@ -238,6 +250,7 @@ class AppProvider with ChangeNotifier {
     _initializeLocationTracking();
     _loadMapEnabled();
     _loadContactsEnabled();
+    _loadContactsSectionVisibility();
     _loadSensorsEnabled();
     _loadVoiceSilenceTrimmingEnabled();
     _loadVoiceBandPassFilterEnabled();
@@ -259,6 +272,27 @@ class AppProvider with ChangeNotifier {
     return ProfileStorageScope.scopedKey(baseKey);
   }
 
+  bool isContactsSectionEnabled(ContactsTabSection section) {
+    return _contactsSectionVisibility[section] ?? true;
+  }
+
+  String _contactsSectionVisibilityKey(ContactsTabSection section) {
+    switch (section) {
+      case ContactsTabSection.favourites:
+        return 'contacts_section_favourites_enabled';
+      case ContactsTabSection.teamMembers:
+        return 'contacts_section_team_members_enabled';
+      case ContactsTabSection.repeaters:
+        return 'contacts_section_repeaters_enabled';
+      case ContactsTabSection.sensors:
+        return 'contacts_section_sensors_enabled';
+      case ContactsTabSection.rooms:
+        return 'contacts_section_rooms_enabled';
+      case ContactsTabSection.channels:
+        return 'contacts_section_channels_enabled';
+    }
+  }
+
   void _startPacketCapturePersistence() {
     _packetCaptureFlushTimer?.cancel();
     _packetCaptureFlushTimer = Timer.periodic(const Duration(seconds: 2), (_) {
@@ -565,6 +599,37 @@ class AppProvider with ChangeNotifier {
     }
   }
 
+  Future<void> _loadContactsSectionVisibility() async {
+    try {
+      final prefs = await SharedPreferences.getInstance();
+      for (final section in ContactsTabSection.values) {
+        _contactsSectionVisibility[section] =
+            prefs.getBool(_scopedKey(_contactsSectionVisibilityKey(section))) ??
+            true;
+      }
+      notifyListeners();
+    } catch (e) {
+      debugPrint('Error loading contacts section visibility settings: $e');
+    }
+  }
+
+  Future<void> setContactsSectionEnabled(
+    ContactsTabSection section,
+    bool enabled,
+  ) async {
+    try {
+      _contactsSectionVisibility[section] = enabled;
+      final prefs = await SharedPreferences.getInstance();
+      await prefs.setBool(
+        _scopedKey(_contactsSectionVisibilityKey(section)),
+        enabled,
+      );
+      notifyListeners();
+    } catch (e) {
+      debugPrint('Error saving contacts section visibility setting: $e');
+    }
+  }
+
   /// Load sensors enabled setting from shared preferences
   Future<void> _loadSensorsEnabled() async {
     try {
@@ -933,9 +998,7 @@ class AppProvider with ChangeNotifier {
         // we also import into firmware so subsequent getContact calls work.
         // Matches the official app which calls cmdGetAdvertPath for all adverts.
         if (source == ContactReceiveSource.advert) {
-          unawaited(
-            connectionProvider.importReceivedAdvert(contact.publicKey),
-          );
+          unawaited(connectionProvider.importReceivedAdvert(contact.publicKey));
         }
         final isNewPendingAdvert = contactsProvider
             .addOrUpdatePendingAdvertContact(
@@ -1352,9 +1415,7 @@ class AppProvider with ChangeNotifier {
       if (_handlePendingRepeaterOwnerResponse(tag, responseData)) {
         return;
       }
-      debugPrint(
-        '📊 [AppProvider] Binary response (0x8C tag=$tag) received',
-      );
+      debugPrint('📊 [AppProvider] Binary response (0x8C tag=$tag) received');
       // Binary responses carry Cayenne LPP telemetry data.
       // The data starts with a channel byte — valid LPP always has at least
       // 3 bytes (channel + type + value). Skip clearly non-telemetry payloads.
@@ -2159,9 +2220,7 @@ class AppProvider with ChangeNotifier {
     // already added to pending adverts and showed notification.
     // Nothing else to do — the callback pipeline handles everything.
     if (wasKnown) {
-      debugPrint(
-        '   [pushAdvert] Existing contact refreshed',
-      );
+      debugPrint('   [pushAdvert] Existing contact refreshed');
     }
   }
 
@@ -2721,6 +2780,7 @@ class AppProvider with ChangeNotifier {
     await Future.wait([
       _loadMapEnabled(),
       _loadContactsEnabled(),
+      _loadContactsSectionVisibility(),
       _loadSensorsEnabled(),
       _loadVoiceSilenceTrimmingEnabled(),
       _loadVoiceBandPassFilterEnabled(),

lib/screens/messages_tab.dart

@@ -28,6 +28,7 @@ import '../services/voice_recorder_service.dart';
 import '../services/voice_codec_service.dart';
 import '../utils/toast_logger.dart';
 import '../utils/key_comparison.dart';
+import '../utils/contact_sorting.dart';
 import '../utils/voice_message_parser.dart';
 import '../utils/image_message_parser.dart';
 import '../utils/tictactoe_message_parser.dart';
@@ -299,27 +300,27 @@ class _MessagesTabState extends State<MessagesTab> {
     final contactsProvider = context.read<ContactsProvider>();
     final normalizedQuery = query.trim().toLowerCase();
     final contacts =
-        contactsProvider.contacts
-            .where((contact) => contact.type == ContactType.chat)
-            .where((contact) {
-              if (normalizedQuery.isEmpty) return true;
-              return contact.displayName.toLowerCase().contains(
-                normalizedQuery,
-              );
-            })
-            .toList()
-          ..sort((a, b) {
-            final aName = a.displayName.toLowerCase();
-            final bName = b.displayName.toLowerCase();
-            final aStarts =
-                normalizedQuery.isNotEmpty && aName.startsWith(normalizedQuery);
-            final bStarts =
-                normalizedQuery.isNotEmpty && bName.startsWith(normalizedQuery);
-            if (aStarts != bStarts) {
-              return aStarts ? -1 : 1;
-            }
-            return aName.compareTo(bName);
-          });
+        contactsProvider.chatContacts.where((contact) {
+          if (normalizedQuery.isEmpty) return true;
+          return contact.displayName.toLowerCase().contains(normalizedQuery);
+        }).toList()..sort((a, b) {
+          final primary = compareContactsByFavouriteThenLastSeen(a, b);
+          if (primary != 0) {
+            return primary;
+          }
+
+          final aName = a.displayName.toLowerCase();
+          final bName = b.displayName.toLowerCase();
+          final aStarts =
+              normalizedQuery.isNotEmpty && aName.startsWith(normalizedQuery);
+          final bStarts =
+              normalizedQuery.isNotEmpty && bName.startsWith(normalizedQuery);
+          if (aStarts != bStarts) {
+            return aStarts ? -1 : 1;
+          }
+
+          return compareContactsByDisplayName(a, b);
+        });
 
     return contacts.take(8).toList(growable: false);
   }
@@ -408,16 +409,33 @@ class _MessagesTabState extends State<MessagesTab> {
     final contactsProvider = context.read<ContactsProvider>();
     final messagesProvider = context.read<MessagesProvider>();
 
-    // Filter contacts by type
-    final contacts = contactsProvider.contacts
-        .where((c) => c.type == ContactType.chat)
-        .toList();
-    final rooms = contactsProvider.contacts
-        .where((c) => c.type == ContactType.room)
-        .toList();
-    final channels = contactsProvider.contacts
-        .where((c) => c.type == ContactType.channel)
-        .toList();
+    final contacts = List<Contact>.from(contactsProvider.chatContacts)
+      ..sort((a, b) {
+        final primary = compareContactsByFavouriteThenLastSeen(a, b);
+        if (primary != 0) {
+          return primary;
+        }
+
+        return compareContactsByDisplayName(a, b);
+      });
+    final rooms = List<Contact>.from(contactsProvider.rooms)
+      ..sort((a, b) {
+        final primary = compareContactsByLastSeen(a, b);
+        if (primary != 0) {
+          return primary;
+        }
+
+        return compareContactsByDisplayName(a, b);
+      });
+    final channels = List<Contact>.from(contactsProvider.channels)
+      ..sort((a, b) {
+        final primary = compareContactsByLastSeen(a, b);
+        if (primary != 0) {
+          return primary;
+        }
+
+        return compareContactsByDisplayName(a, b);
+      });
 
     showModalBottomSheet(
       context: context,
@@ -534,7 +552,10 @@ class _MessagesTabState extends State<MessagesTab> {
         }).firstOrNull;
 
         if (recipient == null) {
-          ToastLogger.error(context, AppLocalizations.of(context)!.cannotReplyContactNotFound);
+          ToastLogger.error(
+            context,
+            AppLocalizations.of(context)!.cannotReplyContactNotFound,
+          );
           return;
         }
       }
@@ -563,13 +584,19 @@ class _MessagesTabState extends State<MessagesTab> {
       } else {
         final senderPrefix = message.senderPublicKeyPrefix;
         if (senderPrefix == null || senderPrefix.length < 6) {
-          ToastLogger.error(context, AppLocalizations.of(context)!.cannotReplySenderMissing);
+          ToastLogger.error(
+            context,
+            AppLocalizations.of(context)!.cannotReplySenderMissing,
+          );
           return;
         }
 
         recipient = contactsProvider.findContactByPrefix(senderPrefix);
         if (recipient == null) {
-          ToastLogger.error(context, AppLocalizations.of(context)!.cannotReplyContactNotFound);
+          ToastLogger.error(
+            context,
+            AppLocalizations.of(context)!.cannotReplyContactNotFound,
+          );
           return;
         }
 

lib/screens/settings_screen.dart

@@ -190,9 +190,11 @@ class _SettingsScreenState extends State<SettingsScreen> {
         _isDeveloperModeEnabled = false;
         _versionTapCount = 0;
       });
-      ScaffoldMessenger.of(
-        context,
-      ).showSnackBar(SnackBar(content: Text(AppLocalizations.of(context)!.developerModeDisabled)));
+      ScaffoldMessenger.of(context).showSnackBar(
+        SnackBar(
+          content: Text(AppLocalizations.of(context)!.developerModeDisabled),
+        ),
+      );
       return;
     }
 
@@ -204,9 +206,11 @@ class _SettingsScreenState extends State<SettingsScreen> {
         _isDeveloperModeEnabled = true;
         _versionTapCount = 0;
       });
-      ScaffoldMessenger.of(
-        context,
-      ).showSnackBar(SnackBar(content: Text(AppLocalizations.of(context)!.developerModeEnabled)));
+      ScaffoldMessenger.of(context).showSnackBar(
+        SnackBar(
+          content: Text(AppLocalizations.of(context)!.developerModeEnabled),
+        ),
+      );
       return;
     }
 
@@ -559,7 +563,9 @@ class _SettingsScreenState extends State<SettingsScreen> {
       if (mounted) {
         ScaffoldMessenger.of(context).showSnackBar(
           SnackBar(
-            content: Text(AppLocalizations.of(context)!.updateCheckIsOnlyAvailableOnAndroid),
+            content: Text(
+              AppLocalizations.of(context)!.updateCheckIsOnlyAvailableOnAndroid,
+            ),
             backgroundColor: Colors.orange,
           ),
         );
@@ -584,7 +590,9 @@ class _SettingsScreenState extends State<SettingsScreen> {
       if (!updateInfo.isAvailable) {
         ScaffoldMessenger.of(context).showSnackBar(
           SnackBar(
-            content: Text(AppLocalizations.of(context)!.youAreRunningTheLatestVersion),
+            content: Text(
+              AppLocalizations.of(context)!.youAreRunningTheLatestVersion,
+            ),
             backgroundColor: Colors.green,
           ),
         );
@@ -594,7 +602,11 @@ class _SettingsScreenState extends State<SettingsScreen> {
       if (updateInfo.downloadUrl == null) {
         ScaffoldMessenger.of(context).showSnackBar(
           SnackBar(
-            content: Text(AppLocalizations.of(context)!.updateAvailableButDownloadUrlNotFound),
+            content: Text(
+              AppLocalizations.of(
+                context,
+              )!.updateAvailableButDownloadUrlNotFound,
+            ),
             backgroundColor: Colors.orange,
           ),
         );
@@ -1178,6 +1190,100 @@ class _SettingsScreenState extends State<SettingsScreen> {
             ),
           ]),
 
+          _buildSectionHeader(AppLocalizations.of(context)!.contacts),
+          Consumer<AppProvider>(
+            builder: (context, appProvider, child) => _buildSettingsCard([
+              SwitchListTile(
+                secondary: const Icon(Icons.star_outline_rounded),
+                title: Text(AppLocalizations.of(context)!.favourites),
+                subtitle: const Text(
+                  'Show the favourites section in the contacts tab',
+                ),
+                value: appProvider.isContactsSectionEnabled(
+                  ContactsTabSection.favourites,
+                ),
+                onChanged: (value) async {
+                  await appProvider.setContactsSectionEnabled(
+                    ContactsTabSection.favourites,
+                    value,
+                  );
+                },
+              ),
+              SwitchListTile(
+                secondary: const Icon(Icons.people_alt_outlined),
+                title: Text(AppLocalizations.of(context)!.teamMembers),
+                subtitle: const Text(
+                  'Show direct team contacts in the contacts tab',
+                ),
+                value: appProvider.isContactsSectionEnabled(
+                  ContactsTabSection.teamMembers,
+                ),
+                onChanged: (value) async {
+                  await appProvider.setContactsSectionEnabled(
+                    ContactsTabSection.teamMembers,
+                    value,
+                  );
+                },
+              ),
+              SwitchListTile(
+                secondary: const Icon(Icons.router_outlined),
+                title: Text(AppLocalizations.of(context)!.repeaters),
+                subtitle: const Text('Show repeater nodes in the contacts tab'),
+                value: appProvider.isContactsSectionEnabled(
+                  ContactsTabSection.repeaters,
+                ),
+                onChanged: (value) async {
+                  await appProvider.setContactsSectionEnabled(
+                    ContactsTabSection.repeaters,
+                    value,
+                  );
+                },
+              ),
+              SwitchListTile(
+                secondary: const Icon(Icons.sensors_outlined),
+                title: Text(AppLocalizations.of(context)!.sensors),
+                subtitle: const Text('Show sensor nodes in the contacts tab'),
+                value: appProvider.isContactsSectionEnabled(
+                  ContactsTabSection.sensors,
+                ),
+                onChanged: (value) async {
+                  await appProvider.setContactsSectionEnabled(
+                    ContactsTabSection.sensors,
+                    value,
+                  );
+                },
+              ),
+              SwitchListTile(
+                secondary: const Icon(Icons.meeting_room_outlined),
+                title: Text(AppLocalizations.of(context)!.rooms),
+                subtitle: const Text('Show rooms in the contacts tab'),
+                value: appProvider.isContactsSectionEnabled(
+                  ContactsTabSection.rooms,
+                ),
+                onChanged: (value) async {
+                  await appProvider.setContactsSectionEnabled(
+                    ContactsTabSection.rooms,
+                    value,
+                  );
+                },
+              ),
+              SwitchListTile(
+                secondary: const Icon(Icons.broadcast_on_personal_outlined),
+                title: Text(AppLocalizations.of(context)!.channels),
+                subtitle: const Text('Show channels in the contacts tab'),
+                value: appProvider.isContactsSectionEnabled(
+                  ContactsTabSection.channels,
+                ),
+                onChanged: (value) async {
+                  await appProvider.setContactsSectionEnabled(
+                    ContactsTabSection.channels,
+                    value,
+                  );
+                },
+              ),
+            ]),
+          ),
+
           _buildSectionHeader('Messaging'),
           _buildSettingsCard([
             ListTile(
@@ -1205,7 +1311,9 @@ class _SettingsScreenState extends State<SettingsScreen> {
             Consumer<AppProvider>(
               builder: (context, appProvider, child) => SwitchListTile(
                 secondary: Icon(Icons.route),
-                title: Text(AppLocalizations.of(context)!.nearestRepeaterFallback),
+                title: Text(
+                  AppLocalizations.of(context)!.nearestRepeaterFallback,
+                ),
                 subtitle: const Text(
                   'After normal retries fail, try one final resend through the nearest repeater',
                 ),
@@ -1234,7 +1342,9 @@ class _SettingsScreenState extends State<SettingsScreen> {
                 'Clear Messages',
                 style: TextStyle(color: Colors.red),
               ),
-              subtitle: Text(AppLocalizations.of(context)!.deleteAllStoredMessageHistory),
+              subtitle: Text(
+                AppLocalizations.of(context)!.deleteAllStoredMessageHistory,
+              ),
               onTap: _clearMessages,
             ),
             Consumer<AppProvider>(
@@ -1344,7 +1454,9 @@ class _SettingsScreenState extends State<SettingsScreen> {
               builder: (context, drawingProvider, child) => SwitchListTile(
                 secondary: Icon(Icons.fmd_good_outlined),
                 title: Text(AppLocalizations.of(context)!.showSarMarkersLabel),
-                subtitle: Text(AppLocalizations.of(context)!.displaySarMarkersOnTheMainMap),
+                subtitle: Text(
+                  AppLocalizations.of(context)!.displaySarMarkersOnTheMainMap,
+                ),
                 value: drawingProvider.showSarMarkers,
                 onChanged: (value) {
                   drawingProvider.toggleSarMarkers();
@@ -1354,7 +1466,9 @@ class _SettingsScreenState extends State<SettingsScreen> {
             Consumer<MapProvider>(
               builder: (context, mapProvider, child) => SwitchListTile(
                 secondary: Icon(Icons.timeline),
-                title: Text(AppLocalizations.of(context)!.showAllContactTrailsLabel),
+                title: Text(
+                  AppLocalizations.of(context)!.showAllContactTrailsLabel,
+                ),
                 subtitle: const Text(
                   'Display location trails for all contacts that have history',
                 ),
@@ -1420,7 +1534,11 @@ class _SettingsScreenState extends State<SettingsScreen> {
               builder: (context, appProvider, child) => SwitchListTile(
                 secondary: Icon(Icons.compress),
                 title: Text(AppLocalizations.of(context)!.voiceCompressor),
-                subtitle: Text(AppLocalizations.of(context)!.balancesQuietAndLoudSpeechLevels),
+                subtitle: Text(
+                  AppLocalizations.of(
+                    context,
+                  )!.balancesQuietAndLoudSpeechLevels,
+                ),
                 value: appProvider.isVoiceCompressorEnabled,
                 onChanged: (value) async {
                   await appProvider.toggleVoiceCompressorEnabled(value);
@@ -1431,7 +1549,11 @@ class _SettingsScreenState extends State<SettingsScreen> {
               builder: (context, appProvider, child) => SwitchListTile(
                 secondary: Icon(Icons.speed),
                 title: Text(AppLocalizations.of(context)!.voiceLimiter),
-                subtitle: Text(AppLocalizations.of(context)!.preventsClippingPeaksBeforeEncoding),
+                subtitle: Text(
+                  AppLocalizations.of(
+                    context,
+                  )!.preventsClippingPeaksBeforeEncoding,
+                ),
                 value: appProvider.isVoiceLimiterEnabled,
                 onChanged: (value) async {
                   await appProvider.toggleVoiceLimiterEnabled(value);
@@ -1442,7 +1564,9 @@ class _SettingsScreenState extends State<SettingsScreen> {
               builder: (context, appProvider, child) => SwitchListTile(
                 secondary: Icon(Icons.auto_fix_high),
                 title: Text(AppLocalizations.of(context)!.micAutoGain),
-                subtitle: Text(AppLocalizations.of(context)!.letsTheRecorderAdjustInputLevel),
+                subtitle: Text(
+                  AppLocalizations.of(context)!.letsTheRecorderAdjustInputLevel,
+                ),
                 value: appProvider.isVoiceAutoGainEnabled,
                 onChanged: (value) async {
                   await appProvider.toggleVoiceAutoGainEnabled(value);
@@ -1478,7 +1602,9 @@ class _SettingsScreenState extends State<SettingsScreen> {
             Consumer<AppProvider>(
               builder: (context, appProvider, child) => SwitchListTile(
                 secondary: Icon(Icons.content_cut),
-                title: Text(AppLocalizations.of(context)!.trimSilenceInVoiceMessages),
+                title: Text(
+                  AppLocalizations.of(context)!.trimSilenceInVoiceMessages,
+                ),
                 subtitle: const Text(
                   'Removes long silent parts before sending voice',
                 ),
@@ -1648,7 +1774,9 @@ class _SettingsScreenState extends State<SettingsScreen> {
             ),
             ListTile(
               leading: Icon(Icons.timer),
-              title: Text(AppLocalizations.of(context)!.activeuseUpdateInterval),
+              title: Text(
+                AppLocalizations.of(context)!.activeuseUpdateInterval,
+              ),
               subtitle: Text('$_fastLocationActiveCadenceSeconds s'),
               trailing: const Icon(Icons.chevron_right),
               onTap: _editFastLocationActiveCadence,

lib/utils/contact_sorting.dart

@@ -0,0 +1,24 @@
+import '../models/contact.dart';
+
+int compareContactsByLastSeen(Contact a, Contact b) {
+  return b.lastSeenTime.compareTo(a.lastSeenTime);
+}
+
+int compareContactsByFavouriteThenLastSeen(Contact a, Contact b) {
+  if (a.isFavourite != b.isFavourite) {
+    return a.isFavourite ? -1 : 1;
+  }
+
+  return compareContactsByLastSeen(a, b);
+}
+
+int compareContactsByDisplayName(Contact a, Contact b) {
+  final nameCompare = a.displayName.toLowerCase().compareTo(
+    b.displayName.toLowerCase(),
+  );
+  if (nameCompare != 0) {
+    return nameCompare;
+  }
+
+  return a.publicKeyHex.compareTo(b.publicKeyHex);
+}

lib/widgets/contacts/contact_tile.dart

@@ -54,6 +54,14 @@ class ContactTile extends StatelessWidget {
     return l10n.daysAgo(diff.inDays);
   }
 
+  String _threeBytePrefix() {
+    final bytes = contact.publicKey.take(3);
+    return bytes
+        .map((byte) => byte.toRadixString(16).padLeft(2, '0'))
+        .join()
+        .toUpperCase();
+  }
+
   @override
   Widget build(BuildContext context) {
     final isChannel = contact.type == ContactType.channel;
@@ -205,46 +213,73 @@ class ContactTile extends StatelessWidget {
           child: Padding(
             padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 10),
             child: Row(
-              crossAxisAlignment: CrossAxisAlignment.center,
+              crossAxisAlignment: CrossAxisAlignment.start,
               children: [
-                Stack(
-                  clipBehavior: Clip.none,
-                  children: [
-                    ContactAvatar(contact: contact, radius: 24),
-                    if (contact.isNew)
-                      Positioned(
-                        top: -2,
-                        right: -2,
-                        child: Container(
-                          width: 14,
-                          height: 14,
-                          decoration: BoxDecoration(
-                            color: Colors.blue,
-                            shape: BoxShape.circle,
-                            border: Border.all(color: Colors.white, width: 2),
-                          ),
+                SizedBox(
+                  width: 58,
+                  child: Column(
+                    mainAxisSize: MainAxisSize.min,
+                    children: [
+                      Stack(
+                        clipBehavior: Clip.none,
+                        children: [
+                          ContactAvatar(contact: contact, radius: 24),
+                          if (contact.isNew)
+                            Positioned(
+                              top: -2,
+                              right: -2,
+                              child: Container(
+                                width: 14,
+                                height: 14,
+                                decoration: BoxDecoration(
+                                  color: Colors.blue,
+                                  shape: BoxShape.circle,
+                                  border: Border.all(
+                                    color: Colors.white,
+                                    width: 2,
+                                  ),
+                                ),
+                              ),
+                            ),
+                          if (contact.type == ContactType.room &&
+                              roomLoginState != null)
+                            Positioned(
+                              bottom: -2,
+                              right: -2,
+                              child: Container(
+                                padding: const EdgeInsets.all(3),
+                                decoration: BoxDecoration(
+                                  color: _getRoomStatusColor(roomLoginState),
+                                  shape: BoxShape.circle,
+                                  border: Border.all(
+                                    color: Colors.white,
+                                    width: 2,
+                                  ),
+                                ),
+                                child: Icon(
+                                  _getRoomStatusIcon(roomLoginState),
+                                  size: 11,
+                                  color: Colors.white,
+                                ),
+                              ),
+                            ),
+                        ],
+                      ),
+                      const SizedBox(height: 8),
+                      Text(
+                        _threeBytePrefix(),
+                        maxLines: 1,
+                        overflow: TextOverflow.ellipsis,
+                        textAlign: TextAlign.center,
+                        style: Theme.of(context).textTheme.labelSmall?.copyWith(
+                          color: colorScheme.onSurfaceVariant,
+                          fontFamily: 'monospace',
+                          fontWeight: FontWeight.w700,
+                          letterSpacing: 0.6,
                         ),
                       ),
-                    if (contact.type == ContactType.room &&
-                        roomLoginState != null)
-                      Positioned(
-                        bottom: -2,
-                        right: -2,
-                        child: Container(
-                          padding: const EdgeInsets.all(3),
-                          decoration: BoxDecoration(
-                            color: _getRoomStatusColor(roomLoginState),
-                            shape: BoxShape.circle,
-                            border: Border.all(color: Colors.white, width: 2),
-                          ),
-                          child: Icon(
-                            _getRoomStatusIcon(roomLoginState),
-                            size: 11,
-                            color: Colors.white,
-                          ),
-                        ),
-                      ),
-                  ],
+                    ],
+                  ),
                 ),
                 const SizedBox(width: 10),
                 Expanded(

test/models/channel_test.dart

@@ -0,0 +1,35 @@
+import 'dart:typed_data';
+
+import 'package:flutter_test/flutter_test.dart';
+import 'package:meshcore_sar_app/models/channel.dart';
+
+void main() {
+  test('hash channels expose deterministic psk_base64', () {
+    final channel = Channel.create(index: 3, name: '#ops');
+
+    expect(channel.isHashChannel, isTrue);
+    expect(channel.pskBase64, 'O2RN43fDLHh5NgWiWqkVvw==');
+    expect(
+      Channel.pskBase64ForHashChannelName('#ops'),
+      'O2RN43fDLHh5NgWiWqkVvw==',
+    );
+  });
+
+  test('normal channels reject derived hashtag psk export helper', () {
+    expect(
+      () => Channel.pskBase64ForHashChannelName('ops'),
+      throwsArgumentError,
+    );
+  });
+
+  test('normal channels still expose their stored psk_base64', () {
+    final channel = Channel.create(
+      index: 4,
+      name: 'ops',
+      explicitSecret: Uint8List.fromList(List<int>.generate(16, (i) => i)),
+    );
+
+    expect(channel.isHashChannel, isFalse);
+    expect(channel.pskBase64, 'AAECAwQFBgcICQoLDA0ODw==');
+  });
+}

test/screens/contacts_tab_test.dart

@@ -1,8 +1,10 @@
 import 'dart:typed_data';
 
 import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:meshcore_sar_app/l10n/app_localizations.dart';
+import 'package:meshcore_sar_app/models/channel.dart';
 import 'package:meshcore_sar_app/models/contact.dart';
 import 'package:meshcore_sar_app/models/contact_group.dart';
 import 'package:meshcore_sar_app/providers/connection_provider.dart';
@@ -15,8 +17,28 @@ import 'package:provider/provider.dart';
 import 'package:shared_preferences/shared_preferences.dart';
 
 void main() {
+  String? clipboardText;
+
   setUp(() {
     SharedPreferences.setMockInitialValues({});
+    clipboardText = null;
+    TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger
+        .setMockMethodCallHandler(SystemChannels.platform, (call) async {
+          switch (call.method) {
+            case 'Clipboard.setData':
+              clipboardText =
+                  (call.arguments as Map<dynamic, dynamic>)['text'] as String?;
+              return null;
+            case 'Clipboard.getData':
+              return <String, dynamic>{'text': clipboardText};
+          }
+          return null;
+        });
+  });
+
+  tearDown(() {
+    TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger
+        .setMockMethodCallHandler(SystemChannels.platform, null);
   });
 
   Contact buildChannel({required String name, required int channelIndex}) {
@@ -123,6 +145,7 @@ void main() {
     await tester.tap(find.text('Ops'));
     await tester.pumpAndSettle();
 
+    expect(find.text('Export psk_base64'), findsNothing);
     expect(find.text('Delete Channel'), findsOneWidget);
 
     await tester.tap(find.text('Delete Channel'));
@@ -137,6 +160,26 @@ void main() {
     );
   });
 
+  testWidgets('hash channel activity card exports psk_base64', (tester) async {
+    await pumpContactsTab(
+      tester,
+      contacts: [buildChannel(name: '#ops', channelIndex: 3)],
+    );
+
+    expect(find.text('#ops'), findsOneWidget);
+    await tester.tap(find.text('#ops'));
+    await tester.pumpAndSettle();
+
+    expect(find.text('Export psk_base64'), findsOneWidget);
+
+    await tester.tap(find.text('Export psk_base64'));
+    await tester.pump();
+    await tester.pump(const Duration(milliseconds: 300));
+
+    expect(clipboardText, Channel.pskBase64ForHashChannelName('#ops'));
+    expect(find.text('psk_base64 copied to clipboard'), findsOneWidget);
+  });
+
   testWidgets('repeaters show Others group when multiple groups exist', (
     tester,
   ) async {
@@ -218,7 +261,7 @@ void main() {
       contacts: [buildSensor(seed: 60, name: 'WX Station')],
     );
 
-    expect(find.text('Sensors'), findsOneWidget);
+    expect(find.text('Sensors'), findsWidgets);
     expect(find.text('WX Station'), findsOneWidget);
   });
 }

test/widgets/recipient_selector_sheet_test.dart

@@ -11,6 +11,8 @@ void main() {
     required String name,
     required ContactType type,
     int secondByte = 0,
+    int flags = 0,
+    int lastAdvert = 0,
   }) {
     final publicKey = Uint8List(32);
     publicKey[1] = secondByte;
@@ -18,11 +20,11 @@ void main() {
     return Contact(
       publicKey: publicKey,
       type: type,
-      flags: 0,
+      flags: flags,
       outPathLen: 0,
       outPath: Uint8List(0),
       advName: name,
-      lastAdvert: 0,
+      lastAdvert: lastAdvert,
       advLat: 0,
       advLon: 0,
       lastMod: 0,
@@ -98,4 +100,54 @@ void main() {
     expect(find.text('Show all'), findsNothing);
     expect(find.text('John Smith'), findsOneWidget);
   });
+
+  testWidgets('sorts contacts with favourites first, then last seen', (
+    tester,
+  ) async {
+    final recentNonFavourite = buildContact(
+      name: 'Alpha',
+      type: ContactType.chat,
+      secondByte: 1,
+      lastAdvert: 300,
+    );
+    final olderFavourite = buildContact(
+      name: 'Bravo',
+      type: ContactType.chat,
+      secondByte: 2,
+      flags: 0x01,
+      lastAdvert: 100,
+    );
+    final newerFavourite = buildContact(
+      name: 'Charlie',
+      type: ContactType.chat,
+      secondByte: 3,
+      flags: 0x01,
+      lastAdvert: 200,
+    );
+
+    await tester.pumpWidget(
+      MaterialApp(
+        localizationsDelegates: AppLocalizations.localizationsDelegates,
+        supportedLocales: AppLocalizations.supportedLocales,
+        home: Scaffold(
+          body: RecipientSelectorSheet(
+            contacts: [recentNonFavourite, olderFavourite, newerFavourite],
+            rooms: const [],
+            channels: const [],
+            unreadCount: 0,
+            unreadCountsByPublicKey: const {},
+            showAllOption: false,
+            onSelect: (selectedRecipient, draftMessage) {},
+          ),
+        ),
+      ),
+    );
+
+    final charlieY = tester.getTopLeft(find.text('Charlie')).dy;
+    final bravoY = tester.getTopLeft(find.text('Bravo')).dy;
+    final alphaY = tester.getTopLeft(find.text('Alpha')).dy;
+
+    expect(charlieY, lessThan(bravoY));
+    expect(bravoY, lessThan(alphaY));
+  });
 }