Honestly you need to go low-tech here. Make it an IR bulb and give the neighbor a cheap IR remote to turn it off.

I also agree with /u/stoatwblr in make sure there’s a cut off for the light.

I solved this issue by hiding the controllers and forcing people to use Home app on iOS.

IR blaster + Home Assistant has been stable enough for me. The IR blaster uses different codes for On vs Off. And I have a temperature sensor near the unit for me to guess if it’s running.