re: the title's build-in measured in the guest's draw stream -- the flashes are real

The settle-time decode was confirmed only against a SETTLED frame, which shows
the end state is right and says nothing about whether the five flashes ever
happen. This runs the oracle: a draw capture armed before the title exists,
so the window contains the frames in which the screen is built.

The flashes fire in a six-frame window and are absent from all 155 other
sampled frames. `ptlogo_back2eff1` is drawn in exactly two frames at t = 54.0
against a decoded peak of t54-56; `ptlogo1` first appears at t = 42.2 against
a decoded t42. Units-per-frame was taken from the GLOW's period alone, a
different element, so the timings are not circular. The two holders are
continuous from frame 134.

The plate glow's quad carries a per-vertex colour whose alpha IS the element's
fade alpha, so the ramp is read straight out of the guest: observed range
0..80 against a decoded peak of 80, exact and unfitted; period 51.158
presented frames over 20 cycle starts. Fitting the decoded ramp gives RMS
13.16 alpha levels against 38.18 for the same ramp REVERSED -- if the shape
carried no information those would be equal, so the asymmetry is real and
correctly directed. Further controls: symmetric triangle 15.73, flat 31.13.

`ptlogo_back2eff3` was never drawn, and that is expected rather than a miss: a
2-unit flash peak is 0.85 of a presented frame, so catching one is a matter of
phase. A port drawing all five every time shows more sweep than the console.

METHOD.md gains the trap this cost: a 2D draw's identity is its vertex
geometry, not its bound texture. These sprites sample shared pages, and
matching texture dimensions produced a false negative (no flash is ever drawn)
and a false positive (the intro movie's 640x360 YUV planes read as `ptbase2`)
in the same pass.

Also records the top-level restriction on the settle window, which the port
raised and which is verified here: top-level [160,236] width 76, including the
`ptloop` leaves [269,540] width 271 -- an instant past the end of every
top-level element's timeline.

Evidence committed as a derived per-frame series, not the 7 MB raw log.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QsEPXWVaEpyfudtR6re1Pd

docs/re/structures/ui-record-loop-length.md

@@ -73,6 +73,23 @@ This is a genuine test rather than a fit: the ring and the plate are different
 elements in different bundles, measured in separate runs, and the only thing tying
 them together is that both declare a 120-unit cycle.
 
+## ✅ Measured in the running game
+
+The glow's quad carries a per-vertex colour whose **alpha is the element's fade
+alpha**, so the ramp can be read straight out of the guest's draw stream
+([`ui-title-buildin-measured.md`](ui-title-buildin-measured.md)):
+
+* **observed alpha range 0 … 80, against a decoded peak of 80** — exact, unfitted;
+* **period 51.158 presented frames** over 20 consecutive cycle starts;
+* the draw is **omitted entirely** while the glow is dark, which is the 11↔10
+  draw alternation visible in the settled title;
+* fitting the decoded ramp gives RMS 13.16 alpha levels against **38.18 for the
+  same ramp reversed** — the asymmetry is real and in the decoded direction.
+
+This does not re-measure the period in seconds (the run's frame rate was not
+recorded), so the falsification below stands on the corpus's wall-clock timings
+rather than on this run.
+
 ## What this replaces
 
 * 🔴 **105 is wrong** and the port should stop shipping it. The number is **120**,