fix(mobile): count only a listed namesake as holding a starter name

Starter setup skipped a starter when a taken-name refusal had a namesake
in the reload that could not serve as the starter. It took any open
namesake for the holder, but an unlisted channel, or a DM, holds no name in
the relay's listed-name rule. A member of an unlisted forum named general
then skipped general for good while the real holder was still settling.

Carry the relay's bare ["unlisted"] kind:39000 flag on Channel, and treat a
namesake as the holder only when it is an open, not unlisted stream or
forum. Otherwise the setup stays recoverable, and a retry joins the real
holder.

Co-authored-by: Larry <627498bd4bd1f281a16431e3c6cce3b5c25b6692798c78672298aefbf2f8f8b5@buzz.block.builderlab.xyz>
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Logan Johnson <loganj@squareup.com>

mobile/lib/app.dart

@@ -129,7 +129,7 @@ class MobileInviteJoinRecovery implements InviteJoinRecovery {
   /// propagates to the invite flow instead of being reported as success. The
   /// one exception is a starter whose name or id the relay reports as taken
   /// by a channel the directory shows cannot serve as the starter, or an
-  /// archived channel at the starter's own id that the directory omits: both
+  /// archived channel at the starter's own id: both
   /// are permanent, so the starter is skipped instead of blocking the join.
   @override
   Future<String?> ensureStarterChannels() async {
@@ -175,9 +175,10 @@ class MobileInviteJoinRecovery implements InviteJoinRecovery {
             // its duplicate check, and keeps that id, so the starter can never
             // be created there.
             if (archivedAtId) continue;
-            // The directory omits archived channels, yet the relay still
-            // keeps the id (desktop uses the same one), so a duplicate with
-            // no match may be an archived starter. Read that id directly.
+            // The relay keeps the id (desktop uses the same one), so a
+            // duplicate with no match in the reload may be an archived
+            // starter whose metadata the reload did not return. Read that id
+            // directly.
             if (!nameTaken && _isDuplicateChannelError(error)) {
               final atId = await _fetchChannel(channelId);
               _ensureScopeCurrent();
@@ -221,9 +222,16 @@ Channel? _findStarterChannel(List<Channel> channels, String name) => channels
     .where((channel) => _hasName(channel, name) && _isUsableStarter(channel))
     .firstOrNull;
 
-/// The open channel that holds [name] in the relay's listed-name rule.
+/// The channel that holds [name] in the relay's listed-name rule: an open,
+/// not unlisted stream or forum (`LISTED_CHANNEL_SQL` in buzz-db).
 Channel? _findListedNamesake(List<Channel> channels, String name) => channels
-    .where((channel) => _hasName(channel, name) && channel.visibility == 'open')
+    .where(
+      (channel) =>
+          _hasName(channel, name) &&
+          channel.visibility == 'open' &&
+          !channel.isUnlisted &&
+          (channel.isStream || channel.isForum),
+    )
     .firstOrNull;
 
 bool _hasName(Channel channel, String name) =>

mobile/lib/features/channels/channel.dart

@@ -30,6 +30,10 @@ class Channel {
   final int? ttlSeconds;
   final DateTime? ttlDeadline;
 
+  /// Left out of listings; such a channel does not hold its name in the
+  /// relay's listed-name rule.
+  final bool isUnlisted;
+
   const Channel({
     required this.id,
     required this.name,
@@ -49,6 +53,7 @@ class Channel {
     this.isMember = false,
     this.ttlSeconds,
     this.ttlDeadline,
+    this.isUnlisted = false,
   });
 
   factory Channel.fromJson(Map<String, dynamic> json) => Channel(
@@ -79,6 +84,7 @@ class Channel {
     ttlDeadline: json['ttl_deadline'] != null
         ? DateTime.parse(json['ttl_deadline'] as String)
         : null,
+    isUnlisted: json['unlisted'] as bool? ?? false,
   );
 
   /// Inverse of [Channel.fromJson].
@@ -101,6 +107,7 @@ class Channel {
     'is_member': isMember,
     'ttl_seconds': ttlSeconds,
     'ttl_deadline': ttlDeadline?.toIso8601String(),
+    'unlisted': isUnlisted,
   };
 
   bool get isEphemeral => ttlSeconds != null || ttlDeadline != null;
@@ -181,6 +188,7 @@ class Channel {
     isMember: isMember,
     ttlSeconds: details.ttlSeconds,
     ttlDeadline: details.ttlDeadline,
+    isUnlisted: isUnlisted,
   );
 
   Channel copyWith({
@@ -213,6 +221,7 @@ class Channel {
     isMember: isMember ?? this.isMember,
     ttlSeconds: ttlSeconds,
     ttlDeadline: ttlDeadline,
+    isUnlisted: isUnlisted,
   );
 }
 

mobile/lib/features/channels/channels_provider.dart

@@ -754,6 +754,7 @@ class ChannelsNotifier extends AsyncNotifier<List<Channel>> {
       isMember: isMember,
       ttlSeconds: data.ttlSeconds,
       ttlDeadline: data.ttlDeadline,
+      isUnlisted: data.isUnlisted,
     );
   }
 

mobile/lib/shared/relay/nostr_models.dart

@@ -298,6 +298,10 @@ class ChannelData {
   final DateTime? ttlDeadline;
   final bool isArchived;
 
+  /// The relay's bare `["unlisted"]` flag: an unlisted channel is left out of
+  /// listings and does not hold its name in the listed-name rule.
+  final bool isUnlisted;
+
   const ChannelData({
     required this.id,
     required this.name,
@@ -311,6 +315,7 @@ class ChannelData {
     this.ttlSeconds,
     this.ttlDeadline,
     this.isArchived = false,
+    this.isUnlisted = false,
   });
 
   factory ChannelData.fromEvent(NostrEvent event) {
@@ -365,6 +370,7 @@ class ChannelData {
       ttlSeconds: ttlSeconds,
       ttlDeadline: ttlDeadline,
       isArchived: isArchived,
+      isUnlisted: event.tags.any((t) => t.isNotEmpty && t[0] == 'unlisted'),
     );
   }
 }

mobile/test/features/channels/channels_provider_test.dart

@@ -2849,7 +2849,7 @@ void main() {
   });
 
   test(
-    'archived kind:39000 metadata sets Channel.isArchived (covers TTL auto-archive)',
+    'archived and unlisted kind:39000 flags reach Channel (covers TTL auto-archive)',
     () async {
       // The relay's TTL reaper auto-archives expired ephemeral channels and
       // republishes kind:39000 with `["archived", "true"]`. The Channel needs
@@ -2864,7 +2864,7 @@ void main() {
           _membership(_channelB, myPk),
         ],
         metadata: [
-          _meta(id: _channelA, name: 'active'),
+          _meta(id: _channelA, name: 'active', unlisted: true),
           _meta(
             id: _channelB,
             name: 'expired-ttl',
@@ -2883,6 +2883,10 @@ void main() {
       // The active channel must not be flagged archived.
       final active = channels.firstWhere((c) => c.name == 'active');
       expect(active.isArchived, isFalse);
+      // The bare `["unlisted"]` flag: an unlisted namesake does not hold a
+      // name in the relay's listed-name rule (starter setup relies on it).
+      expect(active.isUnlisted, isTrue);
+      expect(expired.isUnlisted, isFalse);
     },
   );
 
@@ -3132,6 +3136,7 @@ NostrEvent _meta({
   int createdAt = 1,
   int? ttlSeconds,
   bool archived = false,
+  bool unlisted = false,
   List<String> participants = const [],
 }) => NostrEvent(
   id: 'meta-$id',
@@ -3145,6 +3150,7 @@ NostrEvent _meta({
     [visibility == 'private' ? 'private' : 'public'],
     if (ttlSeconds != null) ['ttl', '$ttlSeconds'],
     if (archived) ['archived', 'true'],
+    if (unlisted) ['unlisted'],
     for (final participant in participants) ['p', participant],
   ],
   content: '',

mobile/test/features/invites/invite_join_provider_test.dart

@@ -564,6 +564,32 @@ void main() {
       expect(unseen.loads(), 2);
       expect(unseen.lookups, isEmpty);
 
+      // An unlisted namesake does not hold the name, so it does not explain
+      // the refusal either: the setup stays recoverable, and a retry joins
+      // the real holder once it appears.
+      final unlistedForum = _channel(
+        id: 'unlisted-general',
+        name: 'general',
+        channelType: 'forum',
+        isUnlisted: true,
+        isMember: true,
+      );
+      final realGeneral = _channel(id: 'real-general', name: 'general');
+      final unlisted = starterSetup(
+        channelsOnLoad: (load) =>
+            load <= 2 ? [unlistedForum] : [unlistedForum, realGeneral],
+        refusalError: refusal,
+      );
+      await expectLater(
+        unlisted.recovery.ensureStarterChannels(),
+        throwsException,
+      );
+      expect(unlisted.created, ['general']);
+      expect(unlisted.joined, isEmpty);
+      final focusAfterRetry = await unlisted.recovery.ensureStarterChannels();
+      expect(unlisted.joined, ['real-general']);
+      expect(focusAfterRetry, welcomeId);
+
       // A usable open channel that appeared after the first load (lost race)
       // is joined rather than skipped.
       final raced = starterSetup(
@@ -1176,11 +1202,13 @@ Channel _channel({
   bool isMember = false,
   String channelType = 'stream',
   DateTime? archivedAt,
+  bool isUnlisted = false,
 }) => Channel(
   id: id,
   name: name,
   channelType: channelType,
   archivedAt: archivedAt,
+  isUnlisted: isUnlisted,
   visibility: visibility,
   description: '',
   createdBy: 'me',