lands on the known tie-break group
Chasing the residual I left open last iteration, and it turns out I had
attributed the port agent's slab to the wrong thing.
First the refutation. My hypothesis was that our dim is applied over the
whole frame rather than beneath the UI where its layer key puts it. If
that were true the logo would render too dark. It reads +2.36 against a
background of -0.74, so the compositor honours the paint order and the
hypothesis is dead.
What the residual actually is: with the dim in place the error is not
uniform but concentrated in one band, running -38.6 in one tile and +33.8
three tiles to its right. Cropping that band from capture and render
shows it immediately -- the game draws the logo's Z swoosh thin with a
pink edge, and we draw it thick and solid white. That, not the missing
dim, is the washed-out slab over the title logo the port agent reported.
The dim explains a uniform +13; this explains the slab.
The elements are ptlogo_back2, its glow, and the five ptlogo_back2eff1..5
segments -- which are also the group carrying this corpus's known
unsolved paint-order tie-break at key 0x8083, on the same screen. I have
recorded that as a lead and explicitly not as a diagnosis, because a
blend-order swap is a poor explanation for white instead of pink and I
would expect a second cause.