at_invitation_flutter is deprecated and has been removed from this repository
as a maintained Flutter package.
Replacement:
packages/at_client_flutter/example/lib/snippets/at_invitation.dart
Last published package:
https://pub.dev/packages/at_invitation_flutter
The invitation flow is now maintained as copy/paste example code for apps using
at_client_flutter. This keeps the core behavior visible without carrying a
separate plugin package, platform folders, custom widget helpers, and package
dependency surface.