It was suggestions from the subreddit and irc that it’s probably a harddrive failure. The kernel devs wanted some more details, but at that point I had already deleted OpenBSD and gone back to Alpine. I might give it a spin again later and if the error happens, I’ll be sure to include the full panic report.

Thanks for suggesting smart, I gave it a spin and it seems the harddrive is healthy?

$ doas smartctl -H /dev/nvme0n1
=== START OF SMART DATA SECTION ===
SMART overall-health self-assessment test result: PASSED

My new suspicion is that I did something funky with the kernel parameters and fstab to try and speed up the system which made it panic.

EDIT: Welp, the issue was with the RAM. Now that’s replaced, all is well.