fix(mobile): tolerate unrelated NIP-11 relay metadata (#8160)

Relay capability additions such as `read_state_snapshot` currently make
mobile push discovery reject otherwise valid NIP-11 documents. This
blocks descriptor-dependent enrollment, lease updates, and remote
revocation.

Read unrelated top-level metadata permissively while preserving
validation of the advertised `nip-pl` extension and the complete push
descriptor. Each returned descriptor value is covered by compatibility
tests; missing or malformed required push fields still fail.

### Validation

- [Codex code
review](https://github.com/block/buzz/pull/8160#issuecomment-6049355700)
and [security
review](https://github.com/block/buzz/pull/8160#issuecomment-6049486587)
completed without findings on the final code.
- Added 24 regression cases covering read-state metadata, arbitrary
future metadata, HTTP discovery, missing/malformed push fields, and
invalid extension advertisements. The six compatibility/discovery cases
fail on unchanged main and pass with the fix.
- All 55 focused descriptor, bootstrap, capability, and revocation tests
pass. Mobile formatting and analysis pass.
- Full mobile gate passes: 3,063 tests passed and four skipped with a
configured gateway, plus all three tests for an unconfigured gateway
build and the gateway recipe checks.
- [Current-head
CI](https://github.com/block/buzz/actions/runs/37706738403) passes,
including Flutter tests, Android debug APK compilation, the complete iOS
simulator app, and the unsigned iOS release build.
- Production HTTP descriptor discovery against live personal-relay
metadata passes without enrollment or relay changes.
- Device enrollment, delivery, notification tap, and opt-out remain to
be exercised in the updated iOS candidate. No relay or device state was
changed.




buzz-review-completed

---------

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

mobile/lib/shared/push/dev_push_lease.dart

@@ -44,33 +44,6 @@ class BuzzPushLeaseDescriptor {
   factory BuzzPushLeaseDescriptor.fromRelayInformation(
     Map<String, dynamic> information,
   ) {
-    _requireExactKeys(
-      information,
-      required: const {},
-      allowed: const {
-        'name',
-        'description',
-        'pubkey',
-        'contact',
-        'supported_nips',
-        'supported_extensions',
-        'software',
-        'version',
-        'limitation',
-        'retention',
-        'relay_countries',
-        'language_tags',
-        'tags',
-        'posting_policy',
-        'payments_url',
-        'fees',
-        'icon',
-        'self',
-        'pairing_relay_url',
-        'push',
-      },
-      name: 'NIP-11 document',
-    );
     final extensions = _stringList(
       information['supported_extensions'],
       name: 'supported_extensions',

mobile/test/shared/push/dev_push_lease_test.dart

@@ -11,6 +11,8 @@ import 'package:buzz/shared/relay/relay_socket.dart';
 import 'package:buzz/shared/relay/signed_event_relay.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:hooks_riverpod/hooks_riverpod.dart';
+import 'package:http/http.dart' as http;
+import 'package:http/testing.dart';
 import 'package:nostr/nostr.dart' as nostr;
 
 void main() {
@@ -298,6 +300,111 @@ void main() {
     expect(jsonDecode(plaintext), jsonDecode(publication.plaintext));
   });
 
+  group('NIP-11 forward compatibility', () {
+    final metadata = <String, Object?>{
+      'read_state_snapshot': {
+        'version': 1,
+        'community_id': '00000000-0000-4000-8000-000000000001',
+        'max_events': 4096,
+        'max_event_array_bytes': 8388608,
+      },
+      'future_object': {
+        'nested': [1, true, null],
+      },
+      'future_array': [1, 'two'],
+      'future_scalar': false,
+      'future_null': null,
+    };
+
+    for (final entry in metadata.entries) {
+      test('ignores unrelated top-level ${entry.key}', () {
+        final information = _descriptorJson(relay.public)
+          ..[entry.key] = entry.value;
+        final parsed = BuzzPushLeaseDescriptor.fromRelayInformation(
+          information,
+        );
+        expect(parsed.origin, descriptor.origin);
+        expect(parsed.executorPubkey, descriptor.executorPubkey);
+        expect(parsed.executorKeyId, descriptor.executorKeyId);
+        expect(parsed.transport, descriptor.transport);
+        expect(parsed.maxLeaseTtlSeconds, descriptor.maxLeaseTtlSeconds);
+        expect(parsed.maxContentLength, descriptor.maxContentLength);
+        expect(parsed.maxPlaintextLength, descriptor.maxPlaintextLength);
+        expect(parsed.maxEndpointLength, descriptor.maxEndpointLength);
+        expect(parsed.maxStringLength, descriptor.maxStringLength);
+      });
+    }
+
+    test('HTTP discovery accepts unrelated metadata', () async {
+      final information = _descriptorJson(relay.public)..addAll(metadata);
+      final client = MockClient((request) async {
+        expect(request.url, Uri.parse('https://tenant.example:8443/'));
+        expect(request.headers['Accept'], 'application/nostr+json');
+        return http.Response(jsonEncode(information), 200);
+      });
+      addTearDown(client.close);
+
+      final parsed = await fetchBuzzPushLeaseDescriptor(
+        'https://tenant.example:8443',
+        client: client,
+      );
+      expect(parsed.executorPubkey, relay.public);
+      expect(parsed.origin, descriptor.origin);
+    });
+
+    for (final field in [
+      'origin',
+      'keys',
+      'app_profiles',
+      'push_kinds',
+      'h_grammar',
+      'class_support',
+      'limitation',
+    ]) {
+      for (final missing in [true, false]) {
+        test(
+          '${missing ? 'missing' : 'malformed'} push.$field fails with future metadata',
+          () {
+            final information = _descriptorJson(relay.public)..addAll(metadata);
+            final push = information['push'] as Map<String, dynamic>;
+            if (missing) {
+              push.remove(field);
+            } else {
+              push[field] = false;
+            }
+            expect(
+              () => BuzzPushLeaseDescriptor.fromRelayInformation(information),
+              throwsA(
+                isA<FormatException>().having(
+                  (error) => error.message,
+                  'rejected field',
+                  contains(field),
+                ),
+              ),
+            );
+          },
+        );
+      }
+    }
+
+    for (final extensions in [
+      null,
+      false,
+      <String>[],
+      ['nip-er'],
+    ]) {
+      test('invalid extension advertisement $extensions fails', () {
+        final information = _descriptorJson(relay.public)
+          ..addAll(metadata)
+          ..['supported_extensions'] = extensions;
+        expect(
+          () => BuzzPushLeaseDescriptor.fromRelayInformation(information),
+          throwsA(isA<FormatException>()),
+        );
+      });
+    }
+  });
+
   test('descriptor rejects canonical origin with a trailing slash', () {
     final information = _descriptorJson(relay.public);
     (information['push'] as Map<String, dynamic>)['origin'] =