Mitja Horvat
3ce17f2146
shutdown_all() was the only remaining sequential shutdown path (TV, then
Gabi, then Gaja — 10+s with SSH timeouts). It now uses the same parallel
_shutdown_devices() as the budget tick, which gained a {dev_id: result}
return value so the button response keeps per-device details and
registry ordering. Per-device failures are isolated instead of being
silently swallowed.