feat(#169): suppress blocked DMs/advert notifs + visible blocked marker

- Connector: BlockService injected via initialize(); incoming DM from a blocked
  key dropped (no thread/unread/notify), advert notifications gated at all 3
  sites (advert still processed for name self-heal). App-push-layer only.
- Contacts + Discovery: blocked entries stay VISIBLE with a red block icon
  (BlockedBadge) + strikethrough/muted name (not hidden).
- New lib/widgets/blocked_badge.dart.

Epic A #165 / A2 #169. Design: docs/architecture/block-contract-as-built.md.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

lib/connector/meshcore_connector.dart

@@ -29,6 +29,7 @@ import '../services/message_retry_service.dart';
 import '../services/path_history_service.dart';
 import '../services/mesh_topology_service.dart';
 import '../services/app_settings_service.dart';
+import '../services/block_service.dart';
 import '../services/background_service.dart';
 import '../services/timeout_prediction_service.dart';
 import '../services/translation_service.dart';
@@ -367,6 +368,7 @@ class MeshCoreConnector extends ChangeNotifier {
   PathHistoryService? _pathHistoryService;
   MeshTopologyService? _topologyService;
   AppSettingsService? _appSettingsService;
+  BlockService? _blockService;
   BackgroundService? _backgroundService;
   final NotificationService _notificationService = NotificationService();
   BleDebugLogService? _bleDebugLogService;
@@ -1009,6 +1011,7 @@ class MeshCoreConnector extends ChangeNotifier {
     AppDebugLogService? appDebugLogService,
     BackgroundService? backgroundService,
     TimeoutPredictionService? timeoutPredictionService,
+    BlockService? blockService,
   }) {
     _retryService = retryService;
     _pathHistoryService = pathHistoryService;
@@ -1019,6 +1022,7 @@ class MeshCoreConnector extends ChangeNotifier {
     _appDebugLogService = appDebugLogService;
     _backgroundService = backgroundService;
     _timeoutPredictionService = timeoutPredictionService;
+    _blockService = blockService;
     _usbManager.setDebugLogService(_appDebugLogService);
     _tcpConnector.setDebugLogService(_appDebugLogService);
 
@@ -4754,7 +4758,9 @@ class MeshCoreConnector extends ChangeNotifier {
       // Show notification for new contact (advertisement)
       if (isNewContact && _appSettingsService != null) {
         final settings = _appSettingsService!.settings;
-        if (settings.notificationsEnabled && settings.notifyOnNewAdvert) {
+        if (settings.notificationsEnabled &&
+            settings.notifyOnNewAdvert &&
+            !(_blockService?.isBlocked(contact.publicKeyHex) ?? false)) {
           _notificationService.showAdvertNotification(
             contactName: contact.name,
             contactType: contact.typeLabelRaw,
@@ -4832,7 +4838,9 @@ class MeshCoreConnector extends ChangeNotifier {
     // Show notification for new contact (advertisement)
     if (isNewContact && _appSettingsService != null) {
       final settings = _appSettingsService!.settings;
-      if (settings.notificationsEnabled && settings.notifyOnNewAdvert) {
+      if (settings.notificationsEnabled &&
+          settings.notifyOnNewAdvert &&
+          !(_blockService?.isBlocked(contact.publicKeyHex) ?? false)) {
         _notificationService.showAdvertNotification(
           contactName: contact.name,
           contactType: contact.typeLabelRaw,
@@ -5005,6 +5013,14 @@ class MeshCoreConnector extends ChangeNotifier {
         return;
       }
 
+      // Blocked sender: drop the DM entirely — no thread entry, no unread, no
+      // notification, no lastMessage bump. Adverts still flow for name self-heal.
+      if (!message.isOutgoing &&
+          (_blockService?.isBlocked(message.senderKeyHex) ?? false)) {
+        _handleQueuedMessageReceived();
+        return;
+      }
+
       final contact = _contacts.cast<Contact?>().firstWhere(
         (c) => c?.publicKeyHex == message!.senderKeyHex,
         orElse: () => null,
@@ -6960,7 +6976,9 @@ class MeshCoreConnector extends ChangeNotifier {
     // Show notification for new contact (advertisement)
     if (_appSettingsService != null && !noNotify) {
       final settings = _appSettingsService!.settings;
-      if (settings.notificationsEnabled && settings.notifyOnNewAdvert) {
+      if (settings.notificationsEnabled &&
+          settings.notifyOnNewAdvert &&
+          !(_blockService?.isBlocked(contact.publicKeyHex) ?? false)) {
         _notificationService.showAdvertNotification(
           contactName: contact.name,
           contactType: contact.typeLabelRaw,

lib/main.dart

@@ -91,6 +91,7 @@ void main() async {
     appDebugLogService: appDebugLogService,
     backgroundService: backgroundService,
     timeoutPredictionService: timeoutPredictionService,
+    blockService: blockService,
   );
 
   await connector.loadContactCache();

lib/screens/contacts_screen.dart

@@ -17,6 +17,7 @@ import '../models/contact.dart';
 import '../l10n/contact_localization.dart';
 import '../models/contact_group.dart';
 import '../services/ui_view_state_service.dart';
+import '../services/block_service.dart';
 import '../utils/contact_search.dart';
 import '../storage/contact_group_store.dart';
 import '../utils/dialog_utils.dart';
@@ -25,6 +26,7 @@ import '../utils/emoji_utils.dart';
 import '../utils/route_transitions.dart';
 import '../widgets/list_filter_widget.dart';
 import '../widgets/empty_state.dart';
+import '../widgets/blocked_badge.dart';
 import '../widgets/quick_switch_bar.dart';
 import '../widgets/path_selection_dialog.dart';
 import '../widgets/repeater_login_dialog.dart';
@@ -1566,6 +1568,9 @@ class _ContactTile extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
+    final isBlocked = context.watch<BlockService>().isBlocked(
+      contact.publicKeyHex,
+    );
     return GestureDetector(
       onSecondaryTapUp: PlatformInfo.isDesktop ? (_) => onLongPress() : null,
       child: ListTile(
@@ -1573,7 +1578,25 @@ class _ContactTile extends StatelessWidget {
           backgroundColor: _getTypeColor(contact.type),
           child: _buildContactAvatar(contact),
         ),
-        title: Text(contact.name, maxLines: 1, overflow: TextOverflow.ellipsis),
+        title: isBlocked
+            ? Row(
+                children: [
+                  const BlockedBadge(),
+                  const SizedBox(width: 6),
+                  Expanded(
+                    child: Text(
+                      contact.name,
+                      maxLines: 1,
+                      overflow: TextOverflow.ellipsis,
+                      style: TextStyle(
+                        color: Theme.of(context).disabledColor,
+                        decoration: TextDecoration.lineThrough,
+                      ),
+                    ),
+                  ),
+                ],
+              )
+            : Text(contact.name, maxLines: 1, overflow: TextOverflow.ellipsis),
         subtitle: Column(
           crossAxisAlignment: CrossAxisAlignment.start,
           children: [

lib/screens/discovery_screen.dart

@@ -12,6 +12,8 @@ import '../utils/contact_search.dart';
 import '../utils/platform_info.dart';
 import '../widgets/app_bar.dart';
 import '../widgets/list_filter_widget.dart';
+import '../widgets/blocked_badge.dart';
+import '../services/block_service.dart';
 import '../helpers/snack_bar_builder.dart';
 
 enum DiscoverySortOption { lastSeen, name, type }
@@ -50,6 +52,7 @@ class _DiscoveryScreenState extends State<DiscoveryScreen> {
   Widget build(BuildContext context) {
     final l10n = context.l10n;
     final connector = context.watch<MeshCoreConnector>();
+    final blockService = context.watch<BlockService>();
 
     final discoveredContacts = connector.discoveredContacts;
     final filteredAndSorted = _filterAndSortContacts(
@@ -97,6 +100,9 @@ class _DiscoveryScreenState extends State<DiscoveryScreen> {
                     itemCount: filteredAndSorted.length,
                     itemBuilder: (context, index) {
                       final contact = filteredAndSorted[index];
+                      final isBlocked = blockService.isBlocked(
+                        contact.publicKeyHex,
+                      );
                       final tile = ListTile(
                         leading: CircleAvatar(
                           backgroundColor: _getTypeColor(contact.type),
@@ -106,7 +112,25 @@ class _DiscoveryScreenState extends State<DiscoveryScreen> {
                             size: 20,
                           ),
                         ),
-                        title: Text(
+                        title: isBlocked
+                            ? Row(
+                                children: [
+                                  const BlockedBadge(),
+                                  const SizedBox(width: 6),
+                                  Expanded(
+                                    child: Text(
+                                      contact.name,
+                                      maxLines: 1,
+                                      overflow: TextOverflow.ellipsis,
+                                      style: TextStyle(
+                                        color: Theme.of(context).disabledColor,
+                                        decoration: TextDecoration.lineThrough,
+                                      ),
+                                    ),
+                                  ),
+                                ],
+                              )
+                            : Text(
                                 contact.name,
                                 maxLines: 1,
                                 overflow: TextOverflow.ellipsis,

lib/widgets/blocked_badge.dart

@@ -0,0 +1,14 @@
+import 'package:flutter/material.dart';
+
+/// Small red "blocked" indicator (circle-with-slash) shown next to a blocked
+/// entry's name in the contacts/discovery lists. Blocked entries stay visible
+/// (not hidden) — see `docs/architecture/block-contract-as-built.md`.
+class BlockedBadge extends StatelessWidget {
+  final double size;
+  const BlockedBadge({super.key, this.size = 16});
+
+  @override
+  Widget build(BuildContext context) {
+    return Icon(Icons.block, size: size, color: Colors.red.shade700);
+  }
+}