[IOS] Would it be possible to support non-embedded browser (so use the default system browser)

I have been using a fork* of this library that adds the use of a default browser to authenticate. I had to use this becasue the way my authentication works is as follows:

- user clicks on login button -> default browser opens (not in-app) -> browser opens authentication app (itsme) -> app opens callback url back in the browser -> browser closes and goes back to app.

This used to work just fine until iOS 18. If I click the login button I just get "error: unable to open Safari."

So I tried using the latest version of flutter_appauth. But then the flow breaks. it looks something like this.

- user clicks on login button -> in-app browser opens -> inapp browser opens authentication app (itsme) -> app opens callback url in default browser (so it doesnt return to the app with the in-app browser open) -> callback show an error.

*the fork: https://github.com/digitalrmdy/flutter_appauth/tree/feature/android-sdk-34

Start by reviewing the authentication flow described in the issue and comparing it with the fork's feature/android-sdk-34 branch. Confirm how the default browser, itsme, and the callback URL are expected to interact on iOS 18; done means the callback returns successfully to the app without the reported Safari or browser error.

Written by the indexing model from the issue text.