re: the capture is settled after all, and the swoosh is undecodable from

the disc

Testing my own caveat instead of leaving it hanging. I had worried the
plate-free title capture at t=4.0s was too early, since elements carry
keyframes out to t=600 and I had judged "settled" from mean luminance,
which cannot see a thin sprite still moving.

The plate sits at y 550-600 and the swoosh band at y 112-225, disjoint,
so a LATE capture works even with the plate present. The band correlates
0.7342 at t=4.0s and 0.7353 at t=21.5s -- identical to a thousandth over
17.5 seconds, with the band mean flat at 127. So the band is settled by
4 seconds, the capture I handed the port agent is sound, and my caveat is
withdrawn. It also corroborates the earlier finding that groups hold:
nothing crosses that band in 22 seconds.

That was the seventh candidate for the swoosh and the last one that was
not a format field. Pivot is inert at scale 100 and there is no
displacement anyway; fade is white-with-alpha; tint is white; the texture
is blue-leaning; additive via +0x04 bit 0x02 makes everything worse; the
capture is settled. The residual is stable and modest -- band mean +1.83,
edge-correlation 0.70 against 0.92 frame-wide.

So I have classified it rather than generating an eighth candidate:
undecodable from the disc, with the reach written out. And I have named
where a next attempt should start, which is not another field -- a
per-draw GPU capture of the running guest reads the actual blend state,
vertex colours and draw order for that band instead of inferring them
from the file. That is where static RE stops here.

docs/port/HANDOFF.md

@@ -109,6 +109,14 @@ authored version can be deleted.
   test is to blend bit-`0x02` sprites additively and re-correlate the title
   against the capture. Note `ptlogo_back2eff` is `0x8830` despite its name, so
   this is a field and not a naming pattern. ❔ Not diagnosed.
+  ❔ **Classified: undecodable from the disc, with reach.** Seven candidates
+  eliminated — pivot (inert at scale 100 *and* no measured displacement), `fade`,
+  `tint`, texture colour, additive blend via `+0x04` bit `0x02`, and
+  capture-not-settled (the band is identical from t = 4.0 s to t = 21.5 s). The
+  residual is stable and modest: band mean **+1.83**, edge-corr **0.70** vs ≈ 0.92
+  frame-wide. A next attempt should use a **per-draw GPU capture** of the running
+  guest, which reads the actual blend state instead of inferring it — not another
+  field. ✅ And the plate-free capture is sound; use it.
   🔴 **Refuted:** it is *not* that our dim covers the whole frame instead of
   sitting beneath the UI — the logo reads +2.36 against a background of −0.74, so
   the paint order is being honoured.