re: the 2D/GP_READY_ROOM blocker - retry already done, two new structural facts

Item: retry the blocker with the "wrong prefix" lesson from
StageMessageSet_S02.tbl. The retry was already run and the owning doc says so:
archive-naming's "13 name transformations" list already includes 2d\, eng\,
hud\ and GP_MAIN_GAME_2D\ prefixes, every one scoring 0 against both the E2D
pak and all 16630 entries. Reading the doc end to end first would have shown
that in a minute. Recorded so the idea is not proposed a third time.

What the re-open did add - two measurements the earlier passes did not make:

1. The six 2D archives share ONE key set: 711 keys, identical in all six.
   Intersection = union = 711; 4266 entries, 711 distinct keys. The entry names
   are language-independent - the language lives in the pak file name, not the
   entry path. That refutes any <lang>\ prefix hypothesis structurally, not
   merely by a zero score: if the names carried a language directory the six
   key sets would differ.

2. The 2D key space is disjoint from the rest of the disc - 0 of 711 appear in
   any non-2D archive, while disc-wide 2010 of 16630 keys are shared between
   archives. Sharing is common; this set never does it.

The six named GP_READY_ROOM entries are all fonts - deu\GOTHICB.TTF, eng\,
esp\, fra\, ita\ likewise, and jpn\HGRGE00.TTF. The doc recorded the count "6
named" without saying what they are: localisation fonts named from elsewhere on
the disc, not a sample of the archive's own artwork vocabulary, so they cannot
seed the dictionary attack the doc names as the last lever. Only 2 of 1106
GP_READY_ROOM keys appear in another archive.

Still blocked, now for a sharper reason: the 2D names are language-independent,
unshared, and absent from disc and executable alike.

All fifteen artefacts byte-identical.

docs/re/structures/archive-naming.md

@@ -250,6 +250,34 @@ rather than improvised around.**
 *content* (T8aD, RATC), and the config records already say which asset each HUD
 element uses. Only the archive-key ↔ name mapping is missing.
 
+## ✅ Two structural facts that tighten the blocker (2026-08-28)
+
+Re-opened to retry the prefix idea after `StageMessageSet_S02.tbl` turned out to
+be a wrong-prefix problem (it resolves under `message\`, not `stage\`). **That
+retry was already done here** — the 13 rewrites above include `2d\`, `eng\`,
+`hud\` and `GP_MAIN_GAME_2D\`, all 0. What the re-open did produce is two
+measurements the earlier passes did not make:
+
+**1. The six 2D archives share ONE key set — 711 keys, identical in all six.**
+Intersection = union = **711**; `4 266` entries, `711` distinct keys. So the
+entry *names are language-independent*: the language lives in the **pak file
+name**, not in the entry path. That refutes any `<lang>\` prefix hypothesis
+**structurally**, not just by a zero score — if the names carried a language
+directory the six key sets would differ.
+
+**2. The 2D key space is disjoint from the rest of the disc.** **0 of the 711**
+appear in any non-2D archive (disc-wide, 2 010 of the 16 630 distinct keys are
+shared between archives, so sharing is common — this set simply does not do it).
+There is no named neighbour to borrow a convention from.
+
+⚠️ **And the six named `GP_READY_ROOM` entries are all fonts** —
+`deu\GOTHICB.TTF`, `eng\`, `esp\`, `fra\`, `ita\` likewise, and
+`jpn\HGRGE00.TTF`. The
+count "6 named" was recorded above without saying *what* they are; they are
+localisation fonts whose names come from elsewhere on the disc, **not a sample of
+the archive's own artwork vocabulary**. So they cannot seed the dictionary attack
+— the lever below still has no corpus.
+
 ## 🟡 Not settled
 
 * What names the 2D and `GP_READY_ROOM` TOCs actually hash. The one lever left is