Converts the cdp-relay-health-monitor from inline SSH (nested quoting
bugs) to a proper self-contained script on bl. Uses pinned ports from
netvm-names.sh as single source of truth.
New files/actions:
- bin/relay-health-check.sh: checks all four CDP relays, exits 0/1
- box-ctl.py relay-health: JSON wrapper for the Box CLI
Session: sidechat/chromebox-ops
operator-main