Visitors hold admin sessions (the editor demo needs is_admin), and some of
them restarted HA from the UI — exit code 100 between hourly resets looked
like stand instability. demo_guard re-registers restart/stop as no-op
services after startup; the hourly docker-level reset is untouched.
stand-reset-timer.js logs a per-minute countdown to the :00 reset in the
browser console (warn for the last 5 minutes); stand-dev-info.js is the
one-shot dev-stand note. Also on the stand host: mem_limit 1536m per
container in compose.yml as an OOM safety net.
