re: B on the main menu goes to the TITLE -- measured, filling an empty evidence cell

menu-navigation-semantics.md had this row at yellow with an EMPTY evidence cell,
and it is what the port still authors as on_cancel.

Delivery-confirmed via [RE-INPUT] (B is kXInputPadB = 0x5801), change detected
rather than timed. B delivered at 331.2 s; the glyph leaves 327 by 331.6 and
73.5 % of pixels differ. Both captures name themselves: PROJECT SYLPHEED with the
(C)2006,2007 SQUARE ENIX line.

Three things measured:
  * B on the main menu goes to the title;
  * latency <= 0.4 s at a 4 Hz sample rate, where the corpus previously had this
    as 'not measured (a backlogged probe void)';
  * NO loading screen in between -- the disc carries four pgloading_* bundles and
    none appears on this path.

What the run CANNOT say, recorded in the table rather than glossed: 'B on the
title -> nothing' is still unevidenced. The second B was delivered during the
title's build-in, so the glyph 0 -> 154 change after it is the build-in
completing, not a response. A run that answers that row must wait for the title
to settle before pressing.

The 're-draws PRESS A after a beat' half of the first row is also still
unevidenced -- the run ended with the plate absent.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Wuu56cE8vJGTBtn1ppsk8v

docs/re/data/b-on-main-menu.txt

@@ -0,0 +1,63 @@
+# What Ⓑ does on the MAIN MENU -- measured 2026-08-30.
+#
+# menu-navigation-semantics.md had this row at 🟡 with an EMPTY evidence cell,
+# and it is what the port still authors as on_cancel.
+#
+# Harness: tools/re-capture/b_from_menu.py -- the plate-pulse title detector,
+# the glyph-327 menu detector, delivery confirmed from [RE-INPUT] rather than
+# from the pad, and change detected rather than timed. B is kXInputPadB =
+# 0x5801 (ui/virtual_key.h:323).
+#
+#   [321.7s] TITLE (glyph 959)
+#   [322.7s] A delivered (attempt 1)
+#   [327.7s] MENU (glyph 327) -- pressing B
+#   [331.2s] B delivered (attempt 1)
+#   [335.0s] screen changed: 73.5 % of pixels differ, glyph 0
+#   [341.3s] glyph 154
+#
+# THE SERIES ACROSS THE PRESS (t : glyph):
+#   326.2 : 0
+#   326.5 : 327
+#   326.7 : 327
+#   326.9 : 327
+#   327.2 : 327
+#   327.4 : 327
+#   327.7 : 327
+#   331.2 : 327
+#   331.6 : 0
+#   332.4 : 0
+#   332.8 : 0
+#   333.3 : 0
+#   333.8 : 0
+#   334.1 : 0
+#   334.5 : 0
+#   335.0 : 0
+#   340.2 : 0
+#   340.5 : 54
+#   340.7 : 154
+#   340.8 : 154
+#   340.9 : 154
+#   341.0 : 154
+#   341.1 : 154
+#   341.2 : 154
+#   341.3 : 154
+#
+# READING: B on the main menu goes to the TITLE. Both captures name
+# themselves -- PROJECT SYLPHEED with the (C)2006,2007 SQUARE ENIX line.
+#   2-after-B-on-menu.png  the title MID-BUILD-IN: wordmark drawn, the green
+#                          copyright line not yet -- which is why glyph is 0
+#                          while 78.0 % of the surface is inked
+#   3-after-B-again.png    copyright drawn, glyph 154 = the plate-absent floor
+#
+# ✅ NO LOADING SCREEN between. The disc carries four pgloading_* bundles and
+# none appears on this path.
+#
+# ✅ LATENCY <= 0.4 s: B delivered at 331.2, glyph leaves 327 by 331.6, at a
+# 4 Hz sample rate. The corpus previously had this as 'not measured (a
+# backlogged probe void)'.
+#
+# 🔴 WHAT THIS RUN CANNOT SAY: 'B on the title -> nothing'. The second B was
+# delivered at 340.2, DURING the title's build-in, so the glyph 0 -> 154
+# change that follows is the build-in completing and not a response. That row
+# stays 🟡 with no evidence, and a run that answers it must wait for the title
+# to SETTLE before pressing.

docs/re/menu-navigation-semantics.md

@@ -23,8 +23,8 @@ with [`tools/re-capture/menu_focus.py`](../../tools/re-capture/menu_focus.py).
 | **wrap at the bottom** | ⬇ from the last item goes to the **first** | same, panels 3→4, and 4 presses from `EXTRAS` landing on `OPTIONS` — i.e. wrapping — is what makes the count come out |
 | **left / right** | **nothing**, on the main menu | cursor unmoved across one ⬅ and one ➡ |
 | **Ⓑ on a submenu** | returns to the parent **with focus restored to the item you entered from** — `LOAD GAME`→`LOAD GAME`, `TUTORIAL`→`TUTORIAL`, `OPTIONS`→`OPTIONS`, `EXTRAS`→`EXTRAS` | 4/4 |
-| **Ⓑ on the main menu** | 🟡 goes to the **title**, which re-draws `PRESS Ⓐ BUTTON` after a beat | **none** — and the main menu's own footer does not advertise Ⓑ; [downgraded below](#-refutation-attempt-2026-08-29--the-main-menus-own-footer-does-not-advertise-ⓑ) |
+| **Ⓑ on the main menu** | ✅ goes to the **title** — measured 2026-08-30, delivery-confirmed, **≤ 0.4 s**, and with **no loading screen** in between. ⚠️ the *"re-draws `PRESS Ⓐ` after a beat"* half is still unevidenced: the run ended with the plate still absent | **1 run** — [`../re/data/b-on-main-menu.txt`](data/b-on-main-menu.txt) · [mid-build-in](captures/title-builds/live-b-on-menu-title-buildin.png) · [settled](captures/title-builds/live-b-on-menu-title-settled.png). The footer point below still stands |
-| **Ⓑ on the title** | 🟡 **nothing** | **none** |
+| **Ⓑ on the title** | 🟡 **nothing** | **none** — ⚠️ and the 2026-08-30 run **cannot** be counted here: its second Ⓑ was delivered *during* the title's build-in, so the glyph 0 → 154 that followed is the build-in completing, not a response. A run that answers this must wait for the title to **settle** first |
 
 Wrap holds on both screens tested — the 5-item main menu and the 3-item `EXTRAS`
 submenu — so it is a menu rule, not a per-screen table.

tools/re-capture/b_from_menu.py

@@ -0,0 +1,125 @@
+#!/usr/bin/env python3
+"""What does Ⓑ do on the MAIN MENU, and then on the TITLE?
+
+`menu-navigation-semantics.md` has those two rows at 🟡 with **empty evidence
+cells** — "goes to the title, which re-draws PRESS Ⓐ after a beat" and "nothing" —
+while `Ⓑ on a submenu` is 4/4 measured. They are what the port still authors as
+`on_cancel`.
+
+Everything here is the harness validated in `tbm-submenu-not-reached.md`:
+the plate-pulse title detector, the glyph-327 menu detector, **delivery confirmed
+from `[RE-INPUT]` rather than from the pad**, and change detected rather than timed.
+Ⓑ is `kXInputPadB = 0x5801` (`ui/virtual_key.h:323`).
+
+    b_from_menu.py LOG OUTDIR [wait_s]
+"""
+import os
+import re
+import subprocess
+import sys
+import time
+
+import numpy as np
+from PIL import Image
+
+LOG, OUT = sys.argv[1], sys.argv[2]
+WAIT = float(sys.argv[3]) if len(sys.argv) > 3 else 480
+W, H = 1280, 720
+NEED, CEIL, HOLD = 500, 2500, 12
+MENU_LO, MENU_HI, MENU_HOLD = 250, 420, 6
+PAD = os.path.join(os.path.dirname(os.path.abspath(__file__)), "pad.py")
+
+
+def deliveries(vk):
+    pat = re.compile((r"RE-INPUT\] XamInputGetKeystrokeEx -> user=\d+ vk=%s flags=0001" % vk).encode())
+    try:
+        return len(pat.findall(open(LOG, "rb").read()))
+    except FileNotFoundError:
+        return 0
+
+
+def press(btn, vk, tries=5):
+    for k in range(tries):
+        before = deliveries(vk)
+        subprocess.run([sys.executable, PAD, "tap", btn, "0.5"], check=False)
+        for _ in range(20):
+            time.sleep(0.25)
+            if deliveries(vk) > before:
+                print(f"[{time.time()-T0:7.1f}s] {btn} delivered (attempt {k+1})", flush=True)
+                return True
+        print(f"[{time.time()-T0:7.1f}s] {btn} NOT delivered (attempt {k+1})", flush=True)
+    return False
+
+
+def _open():
+    return subprocess.Popen(
+        ["ffmpeg", "-loglevel", "error", "-f", "x11grab", "-draw_mouse", "0",
+         "-video_size", f"{W}x{H}", "-i", ":98", "-r", "4",
+         "-f", "rawvideo", "-pix_fmt", "rgb24", "-"],
+        stdout=subprocess.PIPE, bufsize=W * H * 3 * 2)
+
+
+def glyph(a):
+    r, g, b = a[:, :, 0], a[:, :, 1], a[:, :, 2]
+    return int(((g > 130) & (g - r > 45) & (g - b > 45)).sum())
+
+
+T0 = time.time()
+p, n, seg = _open(), W * H * 3, time.time()
+log = open(f"{OUT}/series.tsv", "w"); log.write("# t_s\tglyph\tmean\tphase\n")
+phase, streak, base, stable, mark = "wait", 0, None, 0, None
+while True:
+    el = time.time() - T0
+    if el > WAIT:
+        print(f"TIMEOUT in phase {phase}", flush=True); break
+    if time.time() - seg > 30:
+        p.kill(); p = _open(); seg = time.time()
+    buf = p.stdout.read(n)
+    if len(buf) < n:
+        p.kill(); p = _open(); seg = time.time(); continue
+    a = np.frombuffer(buf, np.uint8).reshape(H, W, 3).astype(int)
+    c = glyph(a)
+    log.write(f"{el:.3f}\t{c}\t{a.mean():.3f}\t{phase}\n"); log.flush()
+    if phase == "wait":
+        streak = streak + 1 if NEED <= c <= CEIL else 0
+        if streak >= HOLD:
+            print(f"[{el:7.1f}s] TITLE (glyph {c})", flush=True)
+            press("A", "5800"); phase, streak = "tomenu", 0
+    elif phase == "tomenu":
+        streak = streak + 1 if MENU_LO <= c <= MENU_HI else 0
+        if streak >= MENU_HOLD:
+            Image.fromarray(a.astype(np.uint8)).save(f"{OUT}/1-menu.png")
+            base = a.astype(float)
+            print(f"[{el:7.1f}s] MENU (glyph {c}) — pressing B", flush=True)
+            time.sleep(2.0)
+            press("B", "5801"); mark = time.time(); phase, stable = "afterB1", 0
+    elif phase == "afterB1":
+        diff = float((np.abs(a - base).max(axis=2) > 12).mean())
+        if diff > 0.25:
+            stable += 1
+            if stable >= 8:
+                Image.fromarray(a.astype(np.uint8)).save(f"{OUT}/2-after-B-on-menu.png")
+                print(f"[{el:7.1f}s] B ON MENU CHANGED THE SCREEN: {100*diff:.1f}% differ, glyph {c}", flush=True)
+                base = a.astype(float); time.sleep(3.0)
+                press("B", "5801"); mark = time.time(); phase, stable = "afterB2", 0
+        else:
+            stable = 0
+            if time.time() - mark > 30:
+                Image.fromarray(a.astype(np.uint8)).save(f"{OUT}/2-after-B-on-menu.png")
+                print(f"[{el:7.1f}s] B ON MENU: NO CHANGE in 30 s ({100*diff:.1f}% differ, glyph {c})", flush=True)
+                base = a.astype(float); press("B", "5801"); mark = time.time(); phase, stable = "afterB2", 0
+    elif phase == "afterB2":
+        diff = float((np.abs(a - base).max(axis=2) > 12).mean())
+        if diff > 0.25:
+            stable += 1
+            if stable >= 8:
+                Image.fromarray(a.astype(np.uint8)).save(f"{OUT}/3-after-B-again.png")
+                print(f"[{el:7.1f}s] SECOND B CHANGED THE SCREEN: {100*diff:.1f}% differ, glyph {c}", flush=True)
+                break
+        else:
+            stable = 0
+            if time.time() - mark > 30:
+                Image.fromarray(a.astype(np.uint8)).save(f"{OUT}/3-after-B-again.png")
+                print(f"[{el:7.1f}s] SECOND B: NO CHANGE in 30 s ({100*diff:.1f}% differ, glyph {c})", flush=True)
+                break
+p.kill(); log.close()