getAllHmacKeys method

@override Future<List<Map<String, dynamic>>> getAllHmacKeys()

Aggregate HMAC keys for every conversation the client knows about (including stitched duplicate DMs). Each entry: {topic: String, hmacKey: Uint8List, thirtyDayPeriodsSinceEpoch: int}. libxmtp returns 3 keys per conversation (prior / current / next epoch). Feed these to the notif server's subscribeWithMetadata so it can filter listener traffic without breaking E2E.

Implementation

@override
Future<List<Map<String, dynamic>>> getAllHmacKeys() {
  throw UnimplementedError(
      'getAllHmacKeys() is not implemented on Web. FCM web-push is out of scope; use the Android/iOS clients for push notifications.');
}