The best way is to ensure the sketch won't crash! :-P

Joke aside, it might be interesting to see why it might crash. Often, in Java, it is because resources (memory...) are exhausted. Which can be because you allocate memory you never release, even if it is no longer unused (memory leak), for example.

You mention AppleScript, I suppose you plan to run your sketch on Macintosh computers, I fear that's beyond my domain of competence.
But on any system, I think the strategy is to have a side process checking if the main process is still in memory. If not, just restart it!
On a Mac, maybe you can do that with a cron which run shell script doing a pgrep and running the sketch if not found.