Closes#325.
A zone gains an "Import devices by subnet" action: type a CIDR, and every
free device whose IP falls in that range moves into the zone, laid out on a
grid in its free space.
The CIDR is an argument to a one-shot action, never a property of the zone —
it is not submitted with the form, not persisted, and cleared after each run.
So there is no schema change, no migration, and it works in standalone mode.
The trade-off is that a device scanned later does not join the zone by
itself; the user re-runs the import.
Deliberate rules:
- additive — running it twice with two subnets leaves both sets inside, and
a device whose IP stops matching is never ejected
- only unparented devices move. A node nested in a group, a container host
or another zone keeps the parent the user gave it
- canvas furniture (groupRect / group / text) is skipped, and a zone never
swallows another zone
- one history entry per import, so a single Undo reverses the whole thing
Edit mode gets an Import button; add mode has none, since the zone does not
exist yet and a button would look broken — there the CIDR is applied right
after the zone is created.
IPv4 only: the modal rejects an IPv6 CIDR with a message rather than
silently matching nothing.
ha-relevant: yes
Pouzor
d9451f35dc