Support apple-app-site-association configuration

[J-tt]

For iOS webcredentials, apple requires a file to be served to allow the app to authenticate to the remote party.

This file is served from /apple-app-site-association and needs to contain the ID of the App.

It'd be a great addition to the passkey server if it could be configured with App IDs to easily allow this, without having to run it behind a reverse proxy and override the path.

[FlxMgdnz]

Thanks for the suggestion @J-tt. I assume your use case is a mobile app and no web app, correct? Usually, we've always suggested to host the file on your website's domain. But if you're building only a mobile app, with no need for a website at all, we could indeed make your life easier by generating and hosting the file for you.