port: write the runbook P5's gate needs, and correct a misreport of a corrected row

P5's gate is 'a human clicks through it' and no document told a human how. The
commands existed in boot.gd's header and scattered through a twelve-thousand-line
DECISIONS.md, which is this project's own finding about capabilities that live
only in the record, applied to the one milestone that cannot be self-certified.

docs/port/RUNNING.md is 107 lines and every command in it was run before it was
written: build the tree, --boot --play for the cold-start walk, --menu= to skip
the 157 s intro, and a table of what a human should see at each press so the gate
is a judgement about the port rather than about whether they drove it right. It
does not claim P5 is met; it removes the excuse that the gate was hard to attempt.

Three sections exist because a reader would otherwise report the container as a
defect: what is knowingly missing (four of five destinations measured but in other
archives, each printing what it would have opened; NEW GAME's skipped chain as a
stated gap), what this container distorts (720p decodes +6.7-6.9% slow, the dummy
audio driver means you hear nothing, the exit leak line is engine-side at 8 to 8),
and how mod overrides report themselves.

The Decoder reported BLOCKED.md's 'which BGM the menu plays -- not on the disc' as
wrong and themselves as the source. The row has been struck and corrected for
days, and I am telling them rather than silently fixing a live row -- their own
asymmetry, that a wrongly-superseded row removes a live question from both views.

The correction already contains the diagnosis they have just made. It says the
negative is bounded -- the TABLES name no screen -- cites li r5 1103 and the
byte-for-byte wave match, and ends: a row here must quote the reach of a negative,
because a negative summarised without its bound reads as a bigger negative than it
is. Their message reports arriving at the same thing independently. Fourth
instance of the connection failure and the sharpest yet: the three before were an
answer sitting unread, this one was an answer sitting ADDRESSED.

Their method note inverts my own v1-to-v3 story and is the transferable part: my
'a report with a standing false positive is one nobody reads' nearly made them
filter a 40-candidate sweep. Instead they measured what the false positives were
-- guessed infrastructural nouns, 5 of 40; the real category was 'not on the disc'
used as a classification legend -- and reading those found the one that was not.
The noisy report was worth reading carefully exactly once before being made quiet.

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

README.md

@@ -42,6 +42,7 @@ docs/
   re/                 the corpus: findings, refutations, method traps
   game/               how the game is navigated -- menus, modals, flight
   port/               the port's mission, its handoff contract, modding rules
+                      -- and RUNNING.md, which is how you actually start it
   agents/             how the agent team works together
 tools/                capture harnesses, probes, the share tool
 exchange/             transient inter-agent files. NOT in git

docs/port/DECISIONS.md

@@ -9,7 +9,7 @@ dies, which is what this file is for.
 
 <!-- INDEX: generated by tools/port/index-decisions -- do not hand-edit -->
 
-278 sections. Search this before re-deriving anything.
+280 sections. Search this before re-deriving anything.
 
 * [P0 — the exporter, 2026-08-28](#p0--the-exporter-2026-08-28)
 * [P1 — Godot draws the screen, 2026-08-28](#p1--godot-draws-the-screen-2026-08-28)
@@ -289,6 +289,8 @@ dies, which is what this file is for.
 * [Their `ring_row.py` defect, and why it did not reach me](#their-ring_rowpy-defect-and-why-it-did-not-reach-me)
 * [The liveness lesson, applied to the product: a mistyped override was silent](#the-liveness-lesson-applied-to-the-product-a-mistyped-override-was-silent)
 * [Their P3 delivery, taken at the strength they gave it](#their-p3-delivery-taken-at-the-strength-they-gave-it)
+* [`docs/port/RUNNING.md` — the P5 gate needed a human and had no runbook](#docsportrunningmd--the-p5-gate-needed-a-human-and-had-no-runbook)
+* [Their `BGM_103` report: the row was already corrected, and it carries their diagnosis](#their-bgm_103-report-the-row-was-already-corrected-and-it-carries-their-diagnosis)
 
 <!-- /INDEX -->
 ## P0 — the exporter, 2026-08-28
@@ -14030,3 +14032,66 @@ they searched every pak for an 8-button-record build and found none, but the
 search assumed DIFFICULTY's four items pair with `f` variants as `GP_TITLE`'s
 screens do. So what is established is *"not an 8-record `btn`-named build
 anywhere"* — **narrower than "not found"**, and the narrowing is theirs.
+
+## `docs/port/RUNNING.md` — the P5 gate needed a human and had no runbook
+
+P5's gate is *"a human clicks through it"*, and **no document told a human how**.
+The commands existed in `boot.gd`'s header and scattered through a
+twelve-thousand-line `DECISIONS.md` — which is this project's own finding about
+capabilities that live only in the record, applied to the one milestone that
+cannot be self-certified.
+
+`RUNNING.md` is 107 lines and every command in it was run before it was written:
+build the tree, `--boot --play` for the cold-start walk, `--menu=` to skip the
+157 s intro, and a table of **what a human should see at each press** so the gate
+is a judgement about the port rather than about whether they drove it right.
+
+Three sections exist because a reader would otherwise report the container as a
+defect:
+
+* **What is knowingly missing** — four of five main-menu destinations are
+  *measured but in other archives*, and the port prints what it would have opened
+  and why it cannot. `NEW GAME`'s skipped chain is a stated gap, not a sequence.
+* **What this container distorts** — 720p decodes **+6.7 %…+6.9 %** slower than
+  real time here, **you will hear nothing** (dummy audio driver, so *"I heard
+  it"* is not available in this box), and the leak line at exit is engine-side,
+  measured 8 → 8.
+* **Modding** — overrides are announced as read, and inert ones listed at the end.
+
+⚠️ It does not claim P5 is met. It removes the excuse that the gate was hard to
+attempt.
+
+## Their `BGM_103` report: the row was already corrected, and it carries their diagnosis
+
+They reported `BLOCKED.md`'s *"which BGM the menu plays — not on the disc"* as
+wrong and themselves as the source. **The row has been struck and corrected for
+days**, and I am telling them rather than silently "fixing" a live row — the
+asymmetry they themselves named: *a wrongly-superseded row removes a live question
+from both views, and nobody re-checks something already marked handled.*
+
+📌 **And the correction already contains the diagnosis they have just made.** My
+row says the negative is bounded — *"the **tables** (`SOUNDS`, `FILES`, bank
+headers) name no screen"* — cites `li r5, 1103`, the byte-for-byte wave match, and
+ends:
+
+> *"a row here must quote the reach of a negative, because a negative summarised
+> without its bound reads as a bigger negative than it is."*
+
+Their message says the same thing arrived at independently: *"the negative was
+true of the CUE TABLE and I wrote it as a negative about the disc."*
+
+🔴 **Fourth instance of the connection failure, and the sharpest yet:** the
+correction was *about their page*, written in my file, and neither of us connected
+it. The three before were an answer sitting unread; this one was an answer sitting
+**addressed**.
+
+✅ Their method note is the transferable part and it inverts my own v1→v3 story:
+their impossibility sweep printed 40 candidates with a known false-positive rate,
+and my *"a report with a standing false positive is one nobody reads"* nearly made
+them **filter it**. Instead they measured what the false positives actually were —
+guessed infrastructural nouns, 5 of 40; the real category was *"not on the disc"*
+used as a **classification legend** — and reading those turned up the one that was
+not legend at all. **The noisy report was worth reading carefully exactly once
+before being made quiet.** My three-version story is about reports that are
+*permanently* noisy; theirs is about the single careful read that must happen
+first.

docs/port/RUNNING.md

@@ -0,0 +1,107 @@
+# Running the port
+
+**P5's gate is *"a human clicks through it"*, and until now there was no page
+telling a human how.** The commands existed — in `boot.gd`'s header comment and
+scattered through a twelve-thousand-line `DECISIONS.md`. A capability that lives
+only in the record is, to the person who needs it, absent.
+
+Everything below has been run. Where a number is quoted it was measured in this
+container, and where the container distorts it that is said rather than left for
+the reader to discover.
+
+## 1. Build the asset tree
+
+The Godot project reads `export/`, never the disc.
+
+```bash
+cargo run --release -p sylpheed-export -- export --disc /disc --out export
+```
+
+Roughly four minutes, most of it transcoding two movies. It **rewrites `export/`
+wholesale** — never hand-edit anything in there; hand-written decisions live in
+`authored/` beside it, and survive a re-export.
+
+## 2. The P5 walk, from a cold start
+
+```bash
+godot --path port -- --boot --play
+```
+
+This is the one a human should judge. It boots the way the game does — two
+splashes, the `ADV` intro, the title — hands over to the menu on Ⓐ, and then
+**stays live and waits for input**.
+
+| you press | what should happen |
+|---|---|
+| Ⓐ on the title | the main menu opens on **NEW GAME** |
+| ⬆ / ⬇ | one item, wrapping at both ends |
+| ⬅ / ➡ | **nothing** — measured, and implemented as an explicit no-op |
+| Ⓐ on **EXTRAS** | the EXTRAS submenu, opening on **MISSION SELECT** |
+| Ⓑ in EXTRAS | back to the main menu, **on the item you left** |
+| Ⓑ on the main menu | back to the title |
+| Ⓐ on the title again | the menu, **still on the item you left** |
+
+That last row is the one worth checking deliberately: the main menu **remembers
+its cursor**, and every submenu **resets** to its own opening item. Both are
+measured, and they disagree on purpose.
+
+⏱ **The intro is ~157 s.** To skip straight to the menu:
+
+```bash
+godot --path port -- --menu=main_menu
+```
+
+and to drive it unattended:
+
+```bash
+godot --path port -- --menu=main_menu --script=down,down,accept,cancel
+```
+
+🔴 `--script` **without** `--play` or `--menu` refuses and says so. It used to
+parse, be stored, and do nothing.
+
+## 3. What is knowingly missing — not bugs
+
+Four of the five main-menu destinations are **measured but not in this export**:
+they live in other archives (`GP_SAVE_LOAD`, `GP_OPTIONS`, …). Pressing Ⓐ on them
+prints what it would have opened and why it cannot:
+
+```
+(LOAD GAME) opens a screen this export does not carry:
+   The save-slot list is GP_SAVE_LOAD, not in this export. Destination MEASURED.
+```
+
+**EXTRAS is the only Ⓐ-into-a-submenu this milestone can walk**, which is why the
+P5 gate rests on it.
+
+`NEW GAME` is a deliberate gap of a different kind: the real chain is
+NEW GAME → DIFFICULTY → SELECT DATA → the `S00A` movie, and the port **jumps to
+the movie**, printing the two screens it skipped. That is a gap, stated out loud;
+nobody should read the port's behaviour there as the game's.
+
+## 4. What this container distorts
+
+* **No GPU.** 720p Theora decodes **+6.7 % … +6.9 % slower than real time** here
+  (5 runs, both movies, on a quiet box). The boot's printed seconds carry that
+  deficit. It is a property of the machine, not of the port.
+* **No sound card.** Godot falls back to a dummy driver, so **you will hear
+  nothing**. The audio is present and measurable —
+  `docs/port/AUDIO-VERIFICATION.md` answers every audio question without a
+  device, and `tools/port/verify-menu-audio` asserts it — but *"I heard it"* is
+  not available in here.
+* **A leaked-object warning at exit** is engine-side, not the port's. Measured:
+  releasing every reference the port owns moves the count from 8 to 8.
+
+## 5. Modding
+
+`data/mods/` shadows `export/` by path. Each override is announced as it is read,
+and at the end of a run any file that **can never apply** is listed:
+
+```
+mod:   sprites/title/main_menu/ptbase.png  <-  data/mods/...
+mods:  1 file(s) in data/mods can shadow NOTHING -- no such path in the export:
+  inert: sprites/title/TYPO_menu/pteff05.png
+```
+
+A file whose path exists in the export but was simply not read this run is **not**
+listed. See `docs/port/MODDING.md` for the five rules the asset tree keeps.