Clonezilla back up / restore by machine number

Boot menu: "Clonezilla: back up this PC" and "restore this PC" ask for the
machine number and boot Clonezilla (64-bit with Debian shim, or 32-bit
i686 by cpuid) with ocs_repository=smb3://clonezilla:<pw>@server/clonezilla/,
ocs_prerun fetching clonezilla-scripts/pxe-cz.sh and ocs_live_run running
it. The script validates the machine number, saves
<machine>-<YYYY-MM-DD-HHMM> (server time), writes pxe-meta.txt, runs
ocs-chkimg, and restores only that machine's images with -k1 -r after a
typed YES. The old entry is "Clonezilla: manual".

Playbook: clonezilla Samba user for the [clonezilla] share only, password
from clonezilla_smb_password (validated, filled into the menu
placeholder), scripts installed to the web root.

Webapp: Clonezilla backups page lists image folders and zips grouped by
machine number with serial/model/version/check, serial mismatch flag,
delete, move to another machine, streamed tar download, disk space bar
and an explicit keep-last-N retention with preview. Tests and a VM test
plan added.

webapp/config.py

@@ -32,6 +32,8 @@ DISPLAY_TZ = os.environ.get("DISPLAY_TZ", "America/New_York")
 HARDWARE_STATE = os.environ.get("HARDWARE_STATE", "/var/lib/pxe-webapp/hardware-seen.json")
 BIOS_DIR = os.environ.get("BIOS_DIR", "/srv/samba/winpeapps/_shared/BIOS")
 BLANCCO_STATE = os.environ.get("BLANCCO_STATE", "/var/lib/pxe-webapp/blancco-state.json")
+# Clonezilla backups page settings (keep last N per machine, disk warning).
+CLONEZILLA_STATE = os.environ.get("CLONEZILLA_STATE", "/var/lib/pxe-webapp/clonezilla-settings.json")
 # PXE server address the Blancco preferences must point the report share at
 # (blancco-init.sh greps for it too); checked when a release is staged.
 BLANCCO_SERVER = os.environ.get("BLANCCO_SERVER", "172.16.9.1")