Faust Auth doesn't seem to work when using Safari

[ChrisWiegman]

Steps to Reproduce

• Start the example app
• Ensure your headless secret key is set properly
• Preview a post
• Notice that the headless refresh token isn’t saved as a cookie

Expected Behavior

- Auth saves cookie and authenticated content can be fetched.
- Toolbar should work as expected
- Post previews should work as expected

Technical Details

This is how Safari works.

See: #1558 (comment)

Acceptance Criteria

• Document this as a known limitation/issue with Safari over localhost
• Consider ways to surface this within the Faust plugin when the appropriate conditions exist

[jordanmaslyn]

Is this related to #1558?

[mindctrl]

@jordanmaslyn yes. We're going to document Safari's behavior in our docs and look into ways to communicate this in the plugin somewhere when using Safari over http. This was copy/pasted from Jira. We've since had a chat about the limitation and our approach. I'll update the AC in the OP.

[theodesp]

Updated docs: https://faustjs.org/guide/how-to-setup-post-and-page-previews

[mindctrl]

Yesterday we decided that documentation is enough for now. We don't want to add any more UI to the plugin, unless this turns into a bigger problem for those users.