Browser links now point at https://covibe.lassul.us/c (our client, our
relay) instead of my.omp.sh. Nothing collab-related loads off-site.

- ompPackage: llm.omp + omp-collab-autostart.patch (env-driven headless
collab autostart; covibe owns the room id/key).
- relayHost = covibe.lassul.us; browser links use omp's hosted collab-web,
terminal guests use 'omp join'. Sessions enumerable + killable by id.

nixpkgs now ships the pkg_resources->importlib.resources patch and builds
tulir-telethon standalone (python3.14 works), so the overlay override
broke the build via --replace-fail on an already-patched line.