The guest's full-screen pass — the brightness-boosted ticket you hold up at the door. This is the screen the whole stub metaphor was designed for.
Notes. One attendance row → one 8-character code, minted at Join
— Interested never gets one. Characters come from an unambiguous alphabet with 0/O and
1/I/L removed, because this gets read aloud in a dark doorway. The screen caches so it
still works with no signal, and the client raises brightness on open.