I fixed it! It actually ended up being very related to the keyboard backlight issue, interestingly enough.
I spent some time this morning fixing the keyboard backlighting, and on a whim, started searching for audio issues on Arch Linux specifically having to do with Clevo laptops. That led me to https://bbs.archlinux.org/viewtopic.php?id=292139 and a few other items that helped.
On my system, /etc/modprobe.d/alsa-base.conf did not exist, so I created the file manually (which I don’t think is proper, but for the moment it is acceptable), and populated it with the text shared in that link, options snd-hda-intel model=clevo-p950.
I then rebooted and it worked! I now have sound.
Posting for visibility/in case anyone else has a Clevo computer with this issue and doesn’t know what to do about a lack of /etc/modprobe.d/alsa-base.conf, and to have this fix in another place.