Totally broken, but running rails 7 app:update makes these changes

[bglusman]

Some manual merging of portions of these changes may make sense, but this is just result of running app:update and overwriting every file with its output, mostly for reference on some possible further rails 7 work

[thejonroberts]

I also made an attempt in draft PR #760 , check it out if you have a chance. I did it from scratch, going to look through this for bits I may have missed.

[compwron]

Thanks for the inspiration! we have merged the rail7 upgrade :)