keep stale channels hidden during relay switch

Signed-off-by: kenny lopez <klopez4212@gmail.com>

mobile/lib/features/activity/activity_page.dart

@@ -442,6 +442,7 @@ class _WideActivityDetail extends HookWidget {
 
     final navigatorKey = useMemoized(GlobalKey<NavigatorState>.new, [item!.id]);
     return NavigatorPopHandler(
+      key: ValueKey('wide-activity-detail-${item!.id}'),
       onPopWithResult: (_) => navigatorKey.currentState?.maybePop(),
       child: Navigator(
         key: navigatorKey,

mobile/lib/features/channels/channels_provider.dart

@@ -95,8 +95,9 @@ class ChannelsNotifier extends AsyncNotifier<List<Channel>> {
     });
 
     if (sessionState.status != SessionStatus.connected) {
-      // Keep the prior community's cache visible until the new relay connects.
-      if (_hasLoaded) return state.value ?? const [];
+      // Preserve the prior community's cache as previous AsyncValue data while
+      // the new relay connects, but remain loading so consumers cannot expose
+      // stale channels as interactive rows in the new community.
       await connected.future;
     }
 

mobile/lib/features/home/home_page/wide_navigation.dart

@@ -756,6 +756,7 @@ class _WideChannelContent extends HookWidget {
       channel.id,
     ]);
     return NavigatorPopHandler(
+      key: ValueKey('wide-channel-detail-${channel.id}'),
       onPopWithResult: (_) => navigatorKey.currentState?.maybePop(),
       child: Navigator(
         key: navigatorKey,

mobile/test/features/channels/channels_provider_test.dart

@@ -457,11 +457,13 @@ void main() {
           .read(relayConfigProvider.notifier)
           .update(baseUrl: 'https://new-community.example');
       await Future<void>.delayed(Duration.zero);
+      expect(container.read(channelsProvider).isLoading, isTrue);
       expect(container.read(channelsProvider).value?.single.name, 'general');
 
       session.setStatus(SessionStatus.connected);
       await Future<void>.delayed(Duration.zero);
 
+      expect(container.read(channelsProvider).isLoading, isFalse);
       expect(container.read(channelsProvider).value?.single.name, 'random');
     },
   );