#124 CORRECTION: the frame adapter is a Z-REFLECTION, not a pi rotation --

proven by the mech's own pods

The first fix (c5dfb00) negated x AND z. The operator challenged it:
'they couldn't hit rear panels AT ALL -- a 180 rotation couldn't explain
that' -- and a rotation would also have relocated rear damage, not
erased it, while the bench premise (the dummy faces its attacker) was
assumed, never measured.

The zero-premise probe (BT_ASPECT_TEST): four self-impacts at known
WORLD cardinals + one at each weapon's PHYSICAL MUZZLE position -- the
mech's own asymmetric geometry as the left/right anchor. Measured:

* WorldToLocal is a clean R(yaw), no hidden terms (yaws -30/150/40 deg
  all consistent);
* our frame: RIGHT = +X -- SAME as the 1995 ring (W0/W7 = Right*) --
  and FORWARD = -Z, flipped vs the ring's Front*-in-+Z-arc;
* under the pi rotation the pods CROSSED (left muzzle -> rtorso);
  under z-negation every anchor lands its own side.

So: negate local z only, and -- since a reflection reverses angular
direction -- the SelectSlice torso-twist term flips sign with it
(twist was 0 in all probes; twisted-torso verify tracked on #124).

Anchor acceptance (fresh exe, third yaw): LRM15_1 left pod -> ltorso,
LRM15_2 -> right wedges, left/right arm muzzles -> larm/rarm, nose ->
front cells, tail -> rear cells, flank cardinals -> rgun / left wedges.

The BT_ASPECT_TEST probe + BTWeaponMuzzleWorld bridge stay as bench
scalpels.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

context/combat-damage.md

@@ -1012,15 +1012,21 @@ code involved; grammar = the binary ctors @0x49ea48/@0x49e5e4).  Results:
   "Right*", W1/W2 = "Front*" -- with theta = atan2(z,x) from +X toward +Z, the
   mech-local FRONT is the **+Z arc (theta 45-135 deg)** and dead-ahead is the
   W1|W2 SEAM.  (Corrects the earlier #92 comment that put frontal hits in W6.)
-* **⚠ PORT FRAME ADAPTER (#124, fixed 2026-08-03)**: that +Z-forward is the
-  **1995 resolver frame**.  OUR engine's entity frame carries forward along
-  **−Z** (bench-measured: a victim facing its attacker took frontal beams at
-  local z=−4..−10, θ≈270°, resolving the REAR-named cells — which was the whole
-  night-10 field table: rear panels unhittable, Owens flanks CROSSED).  The
-  frames differ by a **π rotation about Y** (rotation, not reflection — the
-  flank observations cross rather than persist), so `ResolveHit` negates
-  local x and z after `WorldToLocal` before the band/wedge math.  A/B verified:
-  frontal fire θ≈1.5 → utorso/dtorso/ltorso/rtorso, zero rear zones.  The
+* **⚠ PORT FRAME ADAPTER (#124, fixed 2026-08-03; corrected same day by the
+  MUZZLE-ANCHOR probe)**: that +Z-forward (and +X-right, from the W0/W7
+  "Right*" names) is the **1995 resolver frame**.  OUR engine frame, measured
+  with the mech's own asymmetric geometry as the anchor (`BT_ASPECT_TEST`:
+  four world-cardinal self-impacts + one at each weapon's physical muzzle):
+  **RIGHT = +X, same as 1995; FORWARD = −Z, flipped** — the LEFT missile pod
+  sits at raw local x=−2.32, the RIGHT at +2.32, and `WorldToLocal` is a clean
+  R(yaw) with no hidden terms (verified at yaws −30°/150°/40°).  The frames
+  differ by a **Z-NEGATION ONLY — a reflection** (the first commit's π
+  rotation CROSSED the pods: the left muzzle resolved rtorso).  `ResolveHit`
+  negates local z; and because a reflection reverses angular direction, the
+  torso-twist term in `SelectSlice` enters with the OPPOSITE sign (twist was 0
+  in every probe — the twisted-torso verify is the tracked follow-up).
+  Anchor acceptance: left pod→ltorso, right pod→right wedges, left/right arm
+  muzzles→larm/rarm, nose→front cells, tail→rear cells, at a third yaw.  The
   separate "one band LOW" Y-signature is #16 (pick-ray parallax), not this.
   Frontal unaimed foot-band hits therefore straddle the RightFoot/LeftFoot
   cells by impact-x sign, and the authored cross-bleed (20% opposite foot,