Replaces the per-drive 'pct set -mpN' bind with ONE permanent parent bind
/mnt/felhom-drives plus host-side felhom-data swaps underneath it (propagates
into the running guest live, no pct, no reboot; C1-immune; confined; fail-closed
when absent). EnsureSharedParent installs a boot unit ordered Before=pve-guests.
ReassertGuestBinds is now a pure host-side reconcile. /disks reports GuestPath +
BoundUnderParent for the controller repoint+gate. Non-hollow tests + companions.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
