FreeBSD 14-to-15 Upgrade (Intel)

This post has the notes I made while upgrading another laptop from FreeBSD 14 to FreeBSD 15. Since my first upgrade was a long and annoying process, I figured I would take notes for the second round. These notes are “how not to do it”, even if the end-result is KDE Plasma Wayland on FreeBSD 15, as desired.