Replace Docker-based zigbee2mqtt with a KISS LXC approach using Alpine
Linux container with Node.js + zigbee2mqtt, matching the HAProxy LXC
pattern. Adds USB serial passthrough for Sonoff Dongle Lite MG21.
- zigbee2mqttctl: Full LXC lifecycle (install, update, check, shell)
- RPCD: LXC diagnostics (lxc, cp210x, serial, container, service)
- api.js: Fix callApply missing params (payload was silently dropped)
- overview.js: Match new LXC diagnostics, fix applyConfig call
- Makefiles: Replace +dockerd +docker +containerd with +lxc +kmod-usb-serial-cp210x
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>