Closes the open second reading in ui-forced-backdrop.md: that a .tbm contributes
no pixels, leaving 24 of its 62 deciding verdicts harmless rather than correct.
The TUTORIAL screen was reached and captured. It carries a full-screen blue
circuit/hex background. GP_TUTORIAL build 0's element 0 is pubase.tbm with pivot
(640,360) -- 1280x720, the only full-screen TEXTURED element in the bundle; the
one other full-screen element is pueff00.prm, an untextured primitive the colour
census puts at pure black. Our render of the same build is the identical layout
on pure black, 6.0-6.4 % inked against the game's 99.7 %. The only difference is
the background and the only thing it can be is the .tbm.
So the 24 .tbm verdicts are correct rather than harmless, and they are
load-bearing in the full sense. Reach: one .tbm observed; the class question is
settled, the ten other families are not individually seen.
Also: screen render is wrong on every screen carrying a .tbm -- it drops the
background silently, with no diagnostic.
And the identification is worth its own METHOD entry. Two statistical identifiers
were built. Masked correlation FAILED its control, picking EXTRAS over the known
main menu by 0.004 because the shared background dominates. A high-passed variant
PASSED by 1.28x, which is not a margin that licenses identifying an unknown, so it
was not used. The screen says TUTORIAL across the top. Ask whether the artefact
already states the answer before building a matcher.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Wuu56cE8vJGTBtn1ppsk8v
ddc2a8e36b