DOCFIX-147: opentofu/modules/maas-vm-host + modules/netem-link ...

Registers the vcloud host with MAAS as a virsh VM host, and applies tc netem
WAN-simulation parameters -- the two remaining unbuilt mechanisms from the
OpenTofu scope, researched before drafting per instruction.

maas-vm-host uses canonical/maas's maas_vm_host (register the chassis so
MAAS discovers already-existing VMs), deliberately not maas_vm_host_machine
(composes new VMs itself -- takes cores/memory/disks as inputs). Read both
schemas and cross-checked against D-103's explicit "MAAS does NOT compose
new ones" before picking one.

netem-link uses terraform_data (OpenTofu's own recommended replacement for
null_resource) with an SSH-wrapped local-exec provisioner -- confirmed
local-exec runs on the machine invoking tofu apply (Office1 per D-103), not
the vcloud host where the bridges live, so a bare local command would do
nothing useful.

Neither module instantiated: needs a real MAAS zone/pool, the vcloud host's
SSH target, and real netem parameters, none of which exist yet.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QrcJx8TUar7pYAvpGJw57A