configuration.nix [thick-black-cannon]+networking.md: drop pinned NAT66 externalInterface (restore guest egress)

kubernetes [ipv6]: document own-node host IP blackhole, migrate CNI to nixidy, enable schedulable master

iso-build.md+debugging.md: green status, swapfile ordering-cycle root cause, watchdog-tolerance verdict

resume-state.md [kubernetes/docs]: save ipv6-rook cluster state (2026-08-04)

somewhat working, issue with xdg portals I think causing sound to not work