Traefik merge code written by AI, f.e. https://github.com/traefik/traefik/pull/13397
As do Caddy, such as https://github.com/caddyserver/caddy/pull/7492 and https://github.com/caddyserver/caddy/pull/7666

They seem to merge AI code too, from OPs codeberg link: https://github.com/nginx/nginx/pull/1451

I think pivoting to BSD is the easiest way to find solutions that aren’t tainted by AI.
https://www.openbsdhandbook.com/relayd/

An example of OpenBSD denying AI code contributions:
https://marc.info/?l=openbsd-tech&m=177411620801633&w=2

edit: Seems even OpenBSD is tainted nowadays, from your own link https://github.com/openbsd/src/commit/9c2b8e445a0bdfafdd6148b1760f00aa5429627b and https://github.com/openbsd/src/commit/e9af5eb5a61d189327b553b24d0d31f19c64b63f

edit 2: Here’s the only relevant mail threads I found regarding the AI contributions in openbsd
https://marc.info/?l=openbsd-misc&m=177513420401322&w=2
https://marc.info/?l=openbsd-misc&m=177573214912349&w=2

Completely depends on where you are too, my NAS uses ~30W, which means ~22kWh in 30 days, which translated into local electricity costs are 53SEK or $5.39.
It has enough CPU (Intel Celeron J4125) to run my production loads, RAID1 16TB drives and 18GB RAM so it successfully hosts DNS, DHCP, Jellyfin, Vikunja and network shares. And I get the knowledge that it is all local and under my control.

I haven’t done it myself but Eufy cameras seem to be among the easier ones to flash. :)
https://github.com/themactep/thingino-firmware/wiki/Camera:-Eufy-E220-‐-Ingenic-usb-firmware-installation

https://www.youtube.com/shorts/sRiBUtaGxl4

Thingino makes sure your cameras are yours and no one elses, they have a list of cameras that work with it:
https://thingino.com/

(do we still call it that?)

Primary and secondary is what it is usually called today. I know both Microsoft and Cloudflare does at least.
https://www.cloudflare.com/learning/dns/glossary/primary-secondary-dns/