Optional CPU-temperature source for thermal control. Not essential — the
thermal monitor reads CPU temp from psutil and the kernel's /sys/class/thermal
zones first (both work in-container); `sensors` is only a last-resort text
parse for hosts whose sysfs doesn't expose a CPU zone. Added to both the
from-venv and from-scratch runtime stages for completeness.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>