New third producer container (host-poller) owning the server chassis
subsystem, separate from the SAS-shelf poller:
- services/host_sensors.py: in-band IPMI (ipmitool sdr) for Inlet/Exhaust/etc.
+ CPU package temps from coretemp hwmon
- host_poller.py: own single-instance lock + heartbeat (host_poll keys),
restart-storm guard, paced; writes jbod:host_sensors + jbod:host_drives
- move host/on-metal drive collection off the SAS poller to host-poller
(reads jbod:zfs_map for annotation)
- store: generalized lock/meta with a key param; host_sensors + host-poll keys
- mqtt_publisher: publish env/CPU/host-drive temps as entities on the hub
device (JBOD Monitor)
- Dockerfile host-poller target (ipmitool+smartmontools); compose.infra adds
host-poller; build.sh gains host-poller/all
