In short: v580 is available neither in the Debian repos nor in the NV DC D-13 repos, but packages from the NV DC repo for Debian-12 are known to work fine on D-13 as well.
Well, my upcycling project is just causing trouble.
However, I’m a bit at a loss, and I’m reluctant to use a different kernel.
It’s just a new-old temporary workstation, and it doesn’t need to do anything special, so I want to save myself the trouble and so on.
Based on the error message, it sounds like a permissions issue:
Failed to query NVIDIA devices. Please ensure that the NVIDIA device files (/dev/nvidia*) exist, and that user 127 has read and write permissions for those files.
ok, now you REALLY need to do some homework: please do read the official DC drivers installation guide (linked from the wiki I linked before) how to properly install the driver…
the server does suffer from occasional hiccups, but try from another computer or at least a fresh Firefox profile. If this doesn’t help and the problem persists longer than 12 hours, file a bug against wiki.debian.org virtual package including your IP address (sometimes admins get overzealous with spam/AI-crawling blockers).