The gifts could then sit in "quarantine" for a day or so, with an Android phone running AirGuard sitting nearby.

Is it possible to build a "delay fuse" with a CR1216 or CR1616, Nch FET and a 6-pin AVR all inside a CR2032? Yes, with plenty of room to spare for caps[1]

1: https://pbs.twimg.com/media/E_oLLKOVUAItesC?format=png&name=...

e: meant to say delay fuse, not slow [blow] fuse

You can remove the speaker