fix(host): bring up VMware host stack at boot via native systemd units

Build VMs stopped starting after a reboot into a new kernel: vmmon/vmnet
were left unloaded and vmnet1/vmnet8 (DHCP/NAT) never came up, so
vmware-vmx died (status=237/KEYRING) and clones got no IP. Root cause:
the LSB->systemd sysv-generated vmware.service intermittently fails to
generate at early boot ("systemd-sysv-generator: Cannot find unit
vmware.service"), and the existing module-rebuild guard only builds the
modules -- it never loads them or starts vmnet networking.

Add a native vmware-host.service that runs `/etc/init.d/vmware start`
(loads vmmon/vmci + brings up vmnet), ordered after the rebuild guard,
and mask the flaky sysv vmware.service so the native unit is the sole
owner. Provisioned by scripts/install-vmware-host-services.sh and wired
into setup-host-linux.sh (new step 8/9). VMware ships no native unit and
no kernel postinst hook, so this native wrapper around VMware's own
tools is the reliable boot path.

Verified: linked clone boots and gets a vmnet8 DHCP IP.

deploy/systemd/vmware-modules-rebuild.service

@@ -0,0 +1,17 @@
+[Unit]
+Description=Rebuild VMware host modules (vmmon/vmnet) for running kernel if missing
+Documentation=man:vmware-modconfig(1)
+# VMware modules are not DKMS-managed; ensure they exist before vmware-host starts.
+After=local-fs.target
+Before=vmware-host.service
+ConditionPathExists=/usr/bin/vmware-modconfig
+
+[Service]
+Type=oneshot
+RemainAfterExit=yes
+ExecStart=/usr/local/sbin/vmware-modules-rebuild.sh
+# Building modules can take a little while on a cold kernel.
+TimeoutStartSec=600
+
+[Install]
+WantedBy=multi-user.target