The previous fix preserved display state on Stop so Resume could pick
up the multiplexed frame seamlessly — but that's Pause semantics, not
Stop. On a real Arduino, hitting the physical Stop is cutting power:
the next Run must boot from setup(), not continue at the saved PC.
User report on https://velxio.dev/example/uno-7segment :
> empieza a contar, le doy stop en el 6, le doy run y sigue desde 6
stopBoard now:
- calls sim.reset() (was sim.stop()) — CPU back to PC=0
- calls hardResetPinStates() (was the soft resetPinStates) — clears
cached states AND notifies listeners so 7-seg / NeoPixel / LCD
blank out instead of freezing on whatever was lit.
Reset and Stop are now the same cold-boot semantics; Reset still
additionally clears serial output + baud rate. The soft
resetPinStates() helper stays for internal SPICE-classification-only
paths that don't want listener fan-out.