Proxmox's guest-agent exec (PVE/QemuServer/Agent.pm) dies with
"Wide character in subroutine entry" when input-data contains non-ASCII
bytes. The growpart script had Cyrillic comments, so the whole auto-grow
call returned 500 and the FS was never resized. Replace those comments
with ASCII so the script reaches the guest.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>