- roles/snapshot/tasks/main.yml: replace xe CLI with XO REST API
- POST /rest/v0/vms/<uuid>/actions/snapshot?sync=true
- stores returned snapshot UUID as snapshot_id
- baremetal: skips gracefully with warning
- playbooks/snapshot_pre.yml: target linux_hosts only (was all)
- playbooks/linux_patch.yml: remove snapshot + report roles (snapshot is separate step)
- playbooks/site_maintenance.yml: remove bootstrap play (handled per-playbook),
remove windows_patch import (WinRM not implemented)
