re: every weapon placed (declared x mounted, 131); a fourth undeclared table

Partitioned all 131 Weapon.ID records against the two data routes by which a
weapon is ever named - a field name in an EnumWeapon record, and a Turret_NNN
record's WeaponID value:

                    mounted   not mounted
  declared            105         22
  not declared          0          4

105 + 22 + 0 + 4 = 131, with no unexplained cell. Both marginals re-derive
unit-substructure-records' own numbers independently: mounted 105, and
22 + 4 = its "26 weapons no turret mounts".

The empty cell is the result: nothing is mounted without being declared, 0 of
131, so declaration is the superset of mounting. The four undeclared and
unmounted records are therefore reachable by neither route. Each appears
exactly once per pak copy (x6) and only as a Weapon record's ID value; the live
control Weapon_TCAF_DeltaSaber_Beam appears x18 as an EnumWeapon field name and
x228 as a Turret_NNN.WeaponID. That places Weapon_TCAF_DeltaSaber_Laser_Ttrl,
the weapon this pass set out to find, and unifies all four as orphan datasheet
rows.

Recorded as powerless rather than as evidence: the image holds 0 exact strings
for the four, but also 0 for the live control and 0 for Weapon_NULL. Only three
Weapon_-prefixed strings exist at all and 0 contain Ttrl - the executable names
no weapon, so the negative does not discriminate.

New: sweeping EnumWeapon RECORDS rather than the three declared tables gives 130
distinct field names, not 127. The extra three come from a fourth record, pak
key 305595319, resolved as EnumWeapon_TestS01.tbl, carrying Weapon_TestS01_Gun/
_Laser/_Missile. It dangles at both ends - no stage declares it, and its three
weapons are the only declared names with no Weapon.ID record. 130 - 3 = 127
restores the previous pass's union.

All fifteen artefacts byte-identical.

docs/re/BACKLOG.md

@@ -6224,3 +6224,39 @@ has not been shown.
 already in `unit-substructure-records`' "26 weapons no turret mounts", so they
 are unmounted **and** undeclared; `_Laser_Ttrl` is not on that list and is the
 one still to place.
+
+---
+
+## ✅ 2026-08-28 — every weapon placed; and a fourth, undeclared weapon table
+
+Item (a): place `Weapon_TCAF_DeltaSaber_Laser_Ttrl`.
+
+✅ **The declared × mounted partition of all 131 `Weapon.ID` records has no
+unexplained cell**: declared+mounted **105**, declared+unmounted **22**,
+undeclared+mounted **0**, undeclared+unmounted **4**. Both marginals re-derive
+`unit-substructure-records`' own numbers independently (mounted 105; 22+4 = its
+"26 weapons no turret mounts").
+
+🔑 **Nothing is mounted without being declared (0 of 131)** — declaration is the
+superset. So the four orphans are reachable by neither data route; each appears
+only as a `Weapon` record's `ID` value, ×6 (one per pak copy), and nowhere else.
+Control `Weapon_TCAF_DeltaSaber_Beam`: ×18 as an `EnumWeapon` field, ×228 as a
+`Turret_NNN.WeaponID`. That places `_Laser_Ttrl` and unifies all four as orphan
+datasheet rows.
+
+⚠️ **A route with no power, recorded so it is not re-run:** the image holds 0
+exact strings for the four — and also 0 for the live `Weapon_TCAF_DeltaSaber_Beam`
+and 0 for `Weapon_NULL`. Only three `Weapon_`-prefixed strings exist at all, and
+0 contain `Ttrl`. The executable names no weapon; the negative does not
+discriminate.
+
+✅ **New: a fourth `EnumWeapon` record** — pak key **305595319**, resolved as
+**`EnumWeapon_TestS01.tbl`**, three fields (`Weapon_TestS01_{Gun,Laser,Missile}`).
+Sweeping records rather than declared tables gives **130** names, not 127;
+`130 − 3 = 127` restores the earlier union. It dangles at both ends: **no stage
+declares it**, and its three weapons are the only declared names with **no
+`Weapon.ID` record**.
+
+🟡 Not settled: why those four were kept on the disc; whether the debriefing code
+selects the `EX_` key list for challenge missions; which challenge stage is which
+leaderboard mode.