The region VM carves the same 2-plane no-br-ex shape as the tailscale
router/juju controller, at octet 6 (metal-admin service addr + provider-
public egress for image sync). Added is_region_host + REGION_HOST_SUFFIX;
is_two_plane_host now = juju OR tailscale OR region. lib-hosts:
CARVE_AUX_HOSTS gains vr1-dc{0,1}-maas-01 (octet 6, pinned MACs
dc:5c:0b / ff:5c:02). harness r01/emit_region + T34..T35 (63/0).

Bootstrapped BY Office1, so the .6 carve runs --profile admin with all
Office1 racks in --expect-rack (maas-profile-assert matches EXACTLY).
repo-lint 0 fail; gauntlet ALL GREEN (101).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Fg98z7QyzwYUs8fsWCn728