place max_toot_chars in meta object

app/serializers/initial_state_serializer.rb

@@ -22,7 +22,8 @@ class InitialStateSerializer < ActiveModel::Serializer
       invites_enabled: Setting.min_invite_role == 'user',
       mascot: instance_presenter.mascot&.file&.url,
       profile_directory: Setting.profile_directory,
-      trends: Setting.trends,
+	  trends: Setting.trends,
+	  max_toot_chars: StatusLengthValidator::MAX_CHARS,
     }
 
     if object.current_account