re: the game surface is rendering BLACK -- check that before explaining absences

The named experiment was to attach the fast probe at t=0 so the boot
title could not be missed. Done, default config, English:

  2391 frames in 600.4 s = 3.98 fps; max glyph 0; hits 0

Ten minutes sampled four times a second FROM LAUNCH, no green-(A) glyph.
So "the plate only shows in an early boot window I keep missing" is mine
and refuted -- the third explanation refuted in three iterations.

Then the check that should have come first. Splitting the raw root grab
into bands:

  y   0- 44 (GTK menu bar)   100.00% non-black   mean 210.50
  y  45-719 (game surface)     0.08% non-black   mean   0.07

The game is rendering black, reproducibly across back-to-back samples,
while the guest is alive and polling input (XamInputGetKeystrokeEx past
1201 calls) and MEM-WATCH keeps reporting. The crop and every pixel
oracle were correct; there was nothing on the surface to detect.

What this does NOT do is retroactively explain the earlier failures, and
claiming so would be the fourth over-reach in a row. Those runs had
content: run 2 sampled mean 33.1, run 3's classifier measured real
frame-to-frame rmse, the gamma_type=0 run measured mean 122.8. The
failure mode CHANGED over the session; black is the newest and worst.

Hypothesis for the regression, untested: canary's shader/pipeline cache
is 47 MB and was last written 23:49 on Aug 28, during the failed runs,
and this session has kill -9'd the emulator repeatedly. The test is to
move cache* aside and boot again -- one line and one run, not done.

Two METHOD lines: ask whether the screen is drawing anything before
explaining why a feature of it is missing; and a newly found fault does
not retroactively explain older failures.

docs/re/REFUTED.md

@@ -446,3 +446,8 @@ neighbourhood, not just the line.
   withdrawn last iteration for want of evidence, now **reinstated as a
   measurement**: 1 674 dense samples over 420 s, English, zero glyph frames.
   ⚠️ Reach: a mid-run window only; it says nothing about the boot title.
+* "the PRESS Ⓐ plate appears only in the **boot** title window, which mid-run
+  sampling could never catch" → **mine, and refuted.** The fast probe was
+  attached at t=0: **2 391 frames over 600 s at 3.98 fps from launch**, max glyph
+  0. The plate did not appear at any point in the first ten minutes.
+  [`capture-harness-status.md`](capture-harness-status.md)