styx keeps hass/snapserver/mycelium as a plain LAN client on et0 with a
static lease (10.42.0.3) from acheron; 10.42.0.1 now means the router.
Repoint snapclient, mycelium peers, zigbee2mqtt broker, ignavia's tinc
Address and the gg23 extraHosts accordingly.

Intel N355 mini PC, 2x I226-V, UEFI/NVMe disko, systemd-boot. Only
2configs + retiolum + gg23 for now; NIC naming matches styx (et0 uplink,
int0 LAN). Retiolum card in retiolum/ (10.243.11.2), server tag.

update.sh: the hash probes ran under pipefail/errexit, so an expected hash-mismatch build produced an empty result and the script exited without touching the hashes.