port: the publisher residual was a missing black hold -- we had both dismissed it

I carried this as "0.03 s outside a composite bound, probably a property of the
bound rather than the game", and the Decoder agreed. Both wrong, and the way it
was settled is the point: I stopped reasoning about the bound and filmed the
transition.

At 0.05 s the port fell straight out of the publisher's fade into the developer
logos -- mean 5.06 -> 0.32 at t=4.20, then 5.65 at t=4.25. NO BLACK FRAME AT ALL,
where the oracle measures a 0.17-0.23 s pure-black plateau (HANDOFF Q7). The
bound was fine; the port was missing a fifth of a second of black, and had been
since P3.

Authored at 12 units because the boot path has nothing to read it from:
publisher_logo and developer_logos each carry a single palogo_eff0, a 1280x720
primitive with ONE keyframe at t=0 -- static, not a transition ramp. The menus'
quad declares black for 12 units and 12/60 = 0.200 s sits mid-range, so the
number is the disc's where a screen has one.

Filmed after: t=4.25, 4.30, 4.35, 4.40 all at mean 0, then the developer logos at
4.45. publisher interval 4.26 DIFFERS -> 4.47 agrees; developer 3.62 -> 3.73,
still agrees. Settled-frame comparisons untouched, as they should be.

THE LESSON IS THE SHAPE OF THE DISMISSAL, NOT THE NUMBER. "A 0.03 s miss against
a bound composed from two measured ranges plus jitter slack is more likely a
property of the bound" is plausible, was accepted by both of us, and was wrong.
The composite bound is why the miss looked small -- the underlying gap was 0.2 s
-- and a plausible explanation for a small number is how a real defect stays
hidden. The film cost one command.

Also recorded: the Decoder has reproduced across two build-ins that the console
NEVER draws ptlogo_back2eff3 (0 draws against ~5 expected), with sampling phase,
invisible draws and position error all ruled out -- but WHY is not established,
and nothing in eff3's record differs from its neighbours. The port keeps drawing
it, deliberately: dropping an element the disc declares on a measurement with no
mechanism is authoring a behaviour neither agent can derive, and nothing this
port gates on would notice, since the flashes live only in the build-in and
verify-capture compares the settled frame.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01N7FiFFFwbvG2uxdcEh8HyF

authored/timing.json

@@ -128,5 +128,31 @@
   "`tools/port/verify-dwell` compares a transition INTERVAL against the oracle's",
   "visible SPAN plus that hold. What is deleted is the port's need to invent a",
   "duration the disc now states."
+ ],
+ "black_hold_units": 12,
+ "black_hold_why": [
+  "MEASURED, not on the disc for these screens, so it is authored with a why.",
+  "",
+  "HANDOFF Q7: a screen transition is a fade THROUGH BLACK, and the pure-black",
+  "plateau between one screen leaving and the next arriving was measured at",
+  "0.17-0.23 s. The transition quad on the menus declares black for 12 units, and",
+  "12/60 = 0.200 s sits in the middle of that range -- so 12 units is the number,",
+  "and it is the disc's own where a screen carries such a quad.",
+  "",
+  "THE BOOT SPLASHES DO NOT CARRY ONE. `publisher_logo` and `developer_logos`",
+  "each hold a single `palogo_eff0`, a 1280x720 primitive with ONE keyframe at",
+  "t=0 -- static, not a transition ramp. So on the boot path the hold is",
+  "sequencer behaviour and there is nothing to read it from.",
+  "",
+  "🔴 IT HAD NEVER BEEN IMPLEMENTED, and this is what the publisher_logo residual",
+  "was. Filmed at 0.05 s, the port fades the publisher out to a mean of 0.317 at",
+  "t=4.20 s and the developer logos are already at 5.65 by t=4.25 -- NO BLACK",
+  "FRAME AT ALL. The oracle measures a 0.17-0.23 s plateau there. I had recorded",
+  "the miss as '0.03 s, probably an artefact of the bound I composed', and the",
+  "Decoder agreed; we were both wrong. The bound was fine and the port was",
+  "missing a fifth of a second of black.",
+  "",
+  "Delete this the day a screen's own transition quad supplies it on the boot",
+  "path too."
  ]
 }