Deploys the files changed by a git commit range from src/ to a running XC_VM box (src/ maps 1:1 to /home/xc_vm/): full-file tar-over-ssh, status-aware copy/delete/rename, ownership fixup, optional settings-cache rebuild and panel restart. All SSH multiplexes over one ControlMaster socket to stay fail2ban-safe. Developer convenience only — no versions, DB migrations, binaries, or per-server config; use the release archive for real upgrades. Ships a full man-style --help. Ignore the local .dev-sync-state watermark.