mesh/merge-gate pass: builds mesh-host → ace, g14, novox, shanks; no bus step; every machine composes with the change as it did without (4 of 4 compose)
A module puts the operator's account in a group by declaring the account with that group alone.
The node-engine now records each group it added, takes back only those when nothing declared still
asks for them, refuses a group the machine lacks before usermod runs, and states each such account
as its module's resource of kind account: relogin needed while the running session lacks the group.