👽 Support new attachment reference system

lib/models/post.g.dart

@@ -100,12 +100,10 @@ _SnPublisher _$SnPublisherFromJson(Map<String, dynamic> json) => _SnPublisher(
   name: json['name'] as String,
   nick: json['nick'] as String,
   bio: json['bio'] as String? ?? '',
-  pictureId: json['picture_id'] as String?,
   picture:
       json['picture'] == null
           ? null
           : SnCloudFile.fromJson(json['picture'] as Map<String, dynamic>),
-  backgroundId: json['background_id'] as String?,
   background:
       json['background'] == null
           ? null
@@ -131,9 +129,7 @@ Map<String, dynamic> _$SnPublisherToJson(_SnPublisher instance) =>
       'name': instance.name,
       'nick': instance.nick,
       'bio': instance.bio,
-      'picture_id': instance.pictureId,
       'picture': instance.picture?.toJson(),
-      'background_id': instance.backgroundId,
       'background': instance.background?.toJson(),
       'account': instance.account?.toJson(),
       'account_id': instance.accountId,