Remove the 'swipe to delete envelope' feature.

[zachdecook]

I accidentally deleted one of my envelopes some time ago, and now I can't get it back :'(

The swipe to delete feature is WAYY too easy to accidentally do, and it's easy to miss the 'undo' button (or close the app without realizing).

[zachdecook]

One thought is to make it impossible to remove an envelope with a nonzero balance. So if you want to remove it, you must first transfer the money out of it (or into it for the case of a negative balance) .