Implement undo button

[RazYouUp]

Another nice-to-have enhancement is that sometimes I'll accidentally select the wrong thing (e.g. changing my mind and losing the wrong card after a long rest), and while it's usually possible to manually correct this, it's sometimes nice to just be able to roll back the change with the click of a button. The Gloomhaven Helper app has this feature and it really comes in handy there.

[orichalque]

Indeed that would be a great addition but... pretty hard to implement to be honest 😨
We'll think about how to do that ;-) Thanks for opening an issue !