The briefing map is cyan and satisfies every clause of the menu rule (b-r > 30,
r < 45, little white), with no earlier rule claiming it -- so it was labelled
`menu`. That made wait_screen.sh report NEVER REACHED READY ROOM on a run that
had successfully done LOAD GAME -> slot 01 -> YES and was three screens further
on: a working route scored as a failed one, pointing the next debugging step at
an input path that was fine.
Cyan has b and g nearly equal (b-g ~ 5) where the menu's blue leads its green
(b-g ~ 32), so `r < 20 and g > 30 and b - g < 20` separates them; the r floor
keeps the title screen out. The file's own docstring already carried the
briefing's mean as an aside -- it just never had a class.
Verified against all eight signatures the file documents (2 menu variants, title,
ready room, flight, 3 briefing measurements): no regressions, and the captured
briefing image now reads `briefing`.
