re: S00A.wmv confirmed off the running game -- the movie was never

ambiguous, the sampling was

Continuing last iteration's amber rather than starting something new. The
fix was already named there: stop using 5-second screenshots and record
the display.

Recorded with ffmpeg x11grab at 10 fps and matched every 0.5 s. Across
the 25 consecutive samples from capture 5.0 s to 17.5 s the S00A playhead
is strictly non-decreasing -- 1.0 through 11.0 s, advancing at
essentially real time -- with scores at or above 0.96 and four of them at
0.999 or 1.000 against a runner-up in the 0.78-0.83 range. S00A is the
top match on 23 of the 27 frames carrying signal. So MS00A -> S00A.wmv is
decoded from the manifest AND measured off the game, and the intro begins
about 4.5 s after A on the save slot.

The previous attempt's failure is worth its own METHOD line, because it
did not look like a sampling problem: it looked like weak evidence for
the wrong film. Sparse sampling produced contrast-23 frames, a playhead
that would not join up, and one frame preferring ADV. Sampling does not
weaken a signal gracefully; it turns it into noise shaped like a
different answer.

One aside recorded and not chased: in the S00A 5.5-10 s window, ADV also
scores 0.97-0.99 at its OWN monotone playhead of 33.5-37.5 s. Two films
matching strongly with two consistent playheads is not noise -- it reads
as the boot movie being a trailer cut from the story cutscenes, which
also explains why the sparse run kept flipping between them.

docs/port/HANDOFF.md

@@ -140,7 +140,7 @@ authored version can be deleted.
   disc** — this is why the splash is a screen), **`ADVERTISE_MOVIE` → `ADV.wmv`**,
   `STAFF_ROLL` → `SYLPH_HD720p_8M-CBR_2ch.wmv`, **`MS00A` → `S00A.wmv`** (the
   new-game intro, 93.9 s, with subtitle + `VOICE_S00A` + a text overlay),
-  `MS01A` → `S01A.wmv`. ✅ decoded.
+  `MS01A` → `S01A.wmv`. ✅ decoded — and **`S00A.wmv` is now also measured**: matched off the running game at 0.96–1.000 with a strictly monotone playhead over 25 consecutive 0.5 s samples. It starts ~4.5 s after Ⓐ on the save slot.
   **The boot intro and the attract movie are the SAME asset** — there is no
   separate boot slot, and 15 of 19 captured attract frames match `ADV.wmv` with a
   monotonically advancing playhead ending at its full 137 s. One video, not two.
@@ -256,7 +256,6 @@ here until 2026-08-28 and is now settled.)
 | 🟡 | **the paint-order tie-break** (Q3) | eight candidates refuted; costs one element's blend on one screen |
 | 🟡 | **GamePart ids behind the buttons** (Q4) | the *screens* are measured; the ids are a name match onto the executable's class names |
 | ❔ | **the boot transitions in code** (Q6) | bounded as code-not-data, not proven. `sub_821C6458` — the substantial function in `GamePart_Title`'s neighbourhood — has **not been read** |
-| 🟡 | **`MS00A` → `S00A.wmv` watched only weakly** (Q9) | the path completes now, but 5-second screenshots gave a partial playhead, not the clean one the attract test gave. Manifest decode is still the primary evidence |
 | ❔ | **builds 0/1 and 10/11**, the `DELTASABER` plates (Q2) | never seen anywhere in the boot path, the title-side screens or the attract loop. A mission load is the remaining candidate and this container kills runs before one completes |
 
 The first two share one unblocker — an emulator build whose audio path can be