Tap reader
Tap it. AI's off.
Hold this phone to an AI Off tag, or scan the tap card shown on another phone or printed on a device. It works like paying contactless: one tap and everything connected to that switch stops.
Phone to phone: on the phone running the AI, open its switch and choose Show on this phone under Tap card. Scan that screen from this phone. Browsers can't turn a phone into an NFC tag, so a phone shows its card as a QR code.