re: settle_time measured -- the title is drawn at 2 s, not at rest.t s 4.18

The port s boot sequencer paces every screen off rest.t, which is the last hold
keyframe rather than when a screen arrives. Measured on one cold boot: the
container had no Xenia storage root at all, so this is a fresh profile with no
shader cache, the slowest case.

  title build-in (first ink -> art fully drawn)   0.23 s
  title settled -> PRESS A plate on              2.247 s   (disc declares 120 units)
  plate pulse period                            ~2.37 s
  main menu build-in                             0.531 s
  B -> title                                     0.482 s
  A -> menu                                      3.763 s   DO NOT AUTHOR, see below

The title s rest.t is 251 units = 4.183 s and its art is finished at about 2 s,
so a sequencer pacing off rest.t holds it roughly twice as long as the game does.

Instrument controlled before the run: 9/9 on the content classifier including
the movie-frame and difficulty-screen negatives, 4/4 on the plate detector; the
run sampled 7.99 fps against a requested 8 with an independent one-shot grab
cross-checking every 20 s.

Records a refutation attempt of mine that FAILED. The probe s own marks gave a
plate delay of 3.203 s against the corpus s 2.13 s, which on a cold-cache boot
looked like a real effect. It was the instrument: the plate pulse period is an
internal clock for presentation rate and measures 2.369 s here against the
corpus s 2.3, so the run is not slowed, and re-measuring from content gives
2.247 s. The probe s title_static mark fires during the crossfade out of the
attract movie, before the wordmark has drawn -- glyph was still 0 when it fired.

Also a third independent reproduction of the A-path load stall: 13 frames,
1.53 s, surface mean 26.631 against the earlier 14/1.53 and 12/1.39 at 26.626.
This boot had no shader cache, so it is not a warm-cache artefact. Noted that
the earlier pair agreed to six decimals and mine agrees to three.

Reach: one run. The menu build-in and B->title rest on it alone.

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

docs/re/boot-settle-times-measured.md

@@ -0,0 +1,119 @@
+# ✅ `settle_time()` — when each boot screen actually arrives, measured
+
+**Classification: measured.** None of this is on the disc as a settle time. The
+disc declares *keyframes*; when a screen visibly arrives is a property of the
+running game, and the port authors these numbers from this page.
+
+Answers the port's standing ask: its boot sequencer paces every screen off
+`rest.t`, which is the **last hold keyframe** and not when a screen arrives — it
+holds the title for 4.350 s where the build-in is over at about 2 s.
+
+**Run:** one cold boot, 2026-08-29. Container had **no Xenia storage root at
+all**, so this is a fresh profile (`--create_profile_if_none`) with no shader
+cache — the slowest case, deliberately.
+Frame log committed at [`data/boot-settle-run1.tsv`](data/boot-settle-run1.tsv);
+analysis `tools/re-capture/settle_analyse.py`.
+
+## The instrument was controlled first, and then caught being wrong
+
+`title_timing_probe.py --control` passed **9/9** on the content classifier —
+including the movie-frame and `difficulty-screen` negatives — and **4/4** on the
+plate detector, before the run. The run itself sampled **2 107 frames in 263.7 s
+= 7.99 fps against a requested 8**, with an independent one-shot grab every 20 s
+agreeing with the stream to under 1 grey level. So this is not the backlog
+failure mode that cost this corpus four withdrawn durations.
+
+🔴 **And the probe's own `title_static` mark is still biased early — do not use
+it for a duration.** It fires when the classifier first labels a frame
+`title_*` *and* motion is low, which happens **during the crossfade out of the
+attract movie, before the wordmark has drawn**. In this run it fired at
+`t=242.655` while the green-glyph count was still **0**; the title art does not
+reach its steady state until `243.595`. Any `title_static → plate` figure from
+this probe is therefore inflated by about a second.
+
+## The landmarks, taken from content rather than from the probe's marks
+
+The robust landmark is the **glyph plateau**: the title art alone scores a steady
+`glyph = 154` (the corpus's `live-title-build4-no-plate.png` scores 159), and the
+plate takes it past 700.
+
+| landmark | t (s) | how |
+|---|---|---|
+| attract movie ends, first title ink | 243.362 | glyph leaves 0 |
+| **title art fully drawn** | **243.595** | glyph reaches its steady 154 |
+| **`PRESS Ⓐ` plate on** | **245.842** | glyph crosses 400 → 771 |
+| Ⓐ pressed | 250.983 | |
+| ⚠️ guest load stall | 251.601 – 253.135 | 13 byte-identical frames |
+| **main menu arrives** | **254.707** | classifier |
+| **main menu settled** | **255.238** | motion below a run-calibrated floor |
+| Ⓑ pressed | 262.864 | |
+| **title back** | **263.346** | |
+
+### What the port should author
+
+| | measured | ⚠️ |
+|---|---|---|
+| title build-in (first ink → fully drawn) | **0.23 s** | from first ink; **1.63 s** from the first frame the classifier calls `title_*`, which is where the crossfade starts |
+| **title settled → plate on** | **2.247 s** | matches the disc's declared **120 units** |
+| plate pulse period | **≈2.37 s** | trough-to-trough, 248.098 → 250.467 |
+| **main menu build-in** | **0.531 s** | |
+| **Ⓑ → title** | **0.482 s** | |
+| Ⓐ → menu | 3.763 s | 🔴 **do not author** — contains a 1.53 s emulator load stall, below |
+
+🔴 **`rest.t` is confirmed to be the wrong landmark.** The title's `rest.t` is 251
+units = 4.183 s; its art is finished at ~2 s and the plate is on at 2.25 s. A
+sequencer pacing off `rest.t` holds the title roughly twice as long as the game
+does.
+
+## 🟢 A refutation attempt that FAILED — the corpus's 2.13 s plate delay survives
+
+The probe's own marks gave a plate delay of **3.203 s** (`title_static` 242.655 →
+`plate` 245.858), against the corpus's two committed runs at **2.138 / 2.132 s**
+and a declared 120 units ≈ 2.0 s. A 50 % disagreement, from a cold-cache boot, is
+exactly where you would expect the corpus to be wrong.
+
+**It is not. The instrument was.** Two checks:
+
+* **The presentation rate is not depressed in this run.** If the boot were
+  running slow, everything timed in game units would stretch together. The plate
+  **pulse period** is an internal clock for that, and it measures **2.369 s**
+  here against the corpus's ≈2.3 s. The run is not slowed.
+* **Re-measured from content instead of from the probe's mark**, steady title art
+  (`243.595`) → plate on (`245.842`) is **2.247 s** — inside the corpus's range
+  once the ±0.125 s sample interval is allowed for.
+
+✅ So the 2.13 s stands, the 120-unit reading stands, and the 3.203 s is
+`title_static` firing during a crossfade. Recorded because a failed refutation is
+worth as much as a successful one, and because the next person to read the
+probe's `title_static` will otherwise repeat it.
+
+## 🟢 And the load stall reproduces — third independent run, cold cache
+
+[`title-plate-delay-measured.md`](title-plate-delay-measured.md) records a frozen
+frame on the Ⓐ path in two runs: **14 frames (1.53 s)** and **12 frames
+(1.39 s)**, both at surface mean **26.626**, and concludes any Ⓐ→menu figure from
+this harness is an emulator load time rather than a game constant.
+
+This run is a third: **13 frames, 251.601 – 253.135 = 1.53 s, surface mean
+26.631**, labelled `title_plate` throughout.
+
+✅ The claim survives, and is now stronger in a way the earlier runs could not
+show: this boot had **no shader cache at all**, so the stall is not a warm-cache
+artefact. ⚠️ One honest qualification — the earlier note says its two runs agreed
+"to six decimals"; mine agrees only to three (26.631 vs 26.626), so the mean is
+reproducible but not byte-identical across all three.
+
+## Reach
+
+* **One run.** The durations above are one cold boot. The two that are
+  cross-checked against independent evidence — the plate delay, against the
+  corpus's two runs and the disc's 120 units; the load stall, against two prior
+  runs — are the ones to lean on. The menu build-in (0.531 s) and Ⓑ→title
+  (0.482 s) rest on **this run alone** and should be re-taken before anything
+  depends on them closely.
+* **Sampling is 8 fps**, so every landmark carries ±0.125 s, and the guest's own
+  presentation rate cannot be measured from it — 8 fps is far below the ~28 fps
+  the game presents at, so every sample is a distinct guest frame and repeats
+  only appear when the guest itself stalls.
+* The splash dwells are **not** re-measured here; they are already in
+  [`boot-order-and-splash-dwell.md`](boot-order-and-splash-dwell.md).