fix(mobile): skip the hidden-DM check for newly created DMs

A DM the relay just created cannot be in an older visibility snapshot,
so reading it only adds a way to report failure after the DM exists.
Check visibility only when the relay reports a reopen.

Signed-off-by: Tom Brow <tomb@block.xyz>

mobile/lib/features/channels/channel_management_actions.dart

@@ -148,8 +148,9 @@ class ChannelActions {
     // Reopening a hidden DM unhides it, but the relay still accepts the open
     // when that visibility snapshot fails. Check it here so the failure shows
     // and Done can retry, rather than leaving the DM hidden from the sidebar.
+    // A newly created DM cannot be in an older snapshot.
     final pk = _currentPubkey;
-    final hiddenRequest = pk == null
+    final hiddenRequest = pk == null || response?['created'] == true
         ? Future.value(const <NostrEvent>[])
         : _session.fetchHistory(NostrFilters.hiddenDms(pk));
     final channelRequest = findJoinedChannel(channelId);

mobile/test/features/channels/dm_open_latency_test.dart

@@ -75,6 +75,17 @@ void main() {
         actions.openDm(pubkeys: [_peer], waitForChannelList: false),
         throwsStateError,
       );
+      expect(session.visibilityReads, greaterThan(0));
+      // A newly created DM cannot be in an older snapshot, so it skips that
+      // read and cannot fail on it after the relay created the DM.
+      session.created = true;
+      final reads = session.visibilityReads;
+      expect(
+        (await actions.openDm(pubkeys: [_peer], waitForChannelList: false)).id,
+        _dmId,
+      );
+      expect(session.visibilityReads, reads);
+      session.created = false;
       session.hidden = {};
 
       // Hidden-DM resurfacing keeps waiting for the list that clears its
@@ -106,6 +117,8 @@ class _DmSession extends RelaySessionNotifier {
   final String self;
   bool member = true;
   Set<String> hidden = {};
+  bool created = false;
+  int visibilityReads = 0;
   void Function()? onRead;
   final published = <NostrEvent>[];
   Completer<List<NostrEvent>> stalledList = Completer();
@@ -141,7 +154,8 @@ class _DmSession extends RelaySessionNotifier {
       createdAt: event.createdAt,
       kind: event.kind,
       tags: event.tags,
-      content: 'response:${jsonEncode({'channel_id': _dmId})}',
+      content:
+          'response:${jsonEncode({'channel_id': _dmId, 'created': created})}',
       sig: event.sig,
     );
   }
@@ -152,6 +166,7 @@ class _DmSession extends RelaySessionNotifier {
     Duration timeout = const Duration(seconds: 8),
   }) async {
     if (filter.kinds.single == EventKind.dmVisibility) {
+      visibilityReads++;
       expect(filter.tags, {
         '#p': [self],
       });