Steam interprets exit 0 from 'steamos-update check' as 'update applied
successfully' and shows a persistent 'update available' notification.
The SteamOS convention is exit 7 = no update available.
new site-config.nix holds values previously duplicated across hosts:
domain, old_domain, contact_email, timezone, binary_cache (url + pubkey),
dns_servers, lan (cidr + gateway), hosts.{muffin,yarn} (ip/alias/ssh_host_key),
ssh_keys.{laptop,desktop,ci_deploy}.
threaded through specialArgs on all three hosts + home-manager extraSpecialArgs +
homeConfigurations.primary + serverLib. service-configs.nix now takes
{ site_config } as a function arg and drops its https namespace; per-service
domains (gitea/matrix/ntfy/mollysocket/livekit/firefox-sync/grafana) are
derived from site_config.domain. ~15 service files and 6 vm tests migrated.
breakage fixes rolled in:
- home/progs/zen/dark-reader.nix: 5 stale *.gardling.com entries in
disabledFor rewritten to *.sigkill.computer (caddy 301s the old names so
these never fired and the new sigkill urls were getting dark-reader applied)
- modules/desktop-common.nix: drop unused hugepagesz=1G/hugepages=3
kernelParams (no consumer on mreow or yarn; xmrig on muffin still reserves
its own via services/monero/xmrig.nix)
verification: muffin toplevel is bit-identical to pre-refactor baseline.
mreow/yarn toplevels differ only in boot.json kernelParams + darkreader
storage.js (nix-diff verified). deployGuardTest and fail2banVaultwardenTest
(latter exercises site_config.domain via bitwarden.nix) pass.
