fix(physics): S4/AD-65 — the away-from-plane response snaps to the surface, as retail does

Campaign S slice S4, the half that landed. Retail's CTransition::
adjust_offset @0x0050a370 branches on dot(offset, contactPlane.N) at
0x0050a4fa: moving INTO the plane subtracts the normal component
(0x0050a529), moving AWAY calls Plane::snap_to_plane @0x00509c50 —
which preserves X and Y and re-solves ONLY Z so the offset lies in the
plane (the d terms cancel algebraically), no-op under the
0.000199999995f |N.z| epsilon. acdream ran the orthogonal projection in
BOTH directions, shrinking downhill XY travel by cos^2(theta): 25% at
30 degrees, 50% at 45 — AD-65's recorded shortfall, now retired.

The combined Opus review independently re-derived the algebra, the
branch polarity, the epsilon's bit-identity (17b75139), and the
sabotage magnitude (the re-instated projection yields X = 0.75 =
cos^2 30 exactly), and verified the delta is 4 non-comment lines with
the into-plane arm, the crease arm, and both no-plane arms untouched.
Its blast-radius sweep found the away arm exercised but NOT
discriminated by any pre-existing test — every one asserts lower
bounds the snap over-satisfies — so the two new exact-value tests are
the only discriminating coverage, recorded in the test's class doc,
and the felt 33-100% downhill speed-up is the morning gate's one row.

AD-66 (the push-out's bare radius) is WITHHELD: byte-confirmed twice,
implemented, then pulled after the same clean-room binaries measured
contradictory absorbed-tick outcomes flipping with nothing but test
assert shape — issue #341 carries the observation matrix and the
apparatus plan; its two exact-value tests are [Skip]-ed; the retained
substitution's rationale is restored at the site per review F1, with
the review's remaining findings (F2/F3/F4/F5/F6) applied and F8 filed
as #342. AD-69 filed: the same block omits retail's get_block_offset
seam-frame correction, deferred to the AD-66 relanding for
attributability. #340 filed: a fifth load-sensitive flake.

Review verdict: PASS. AD-65 is provably unable to reach the #341
anomaly's code path (the absorb scenario takes the crease arm).
Clean-room suite: 11,239 passed / 6 skipped / 0 failed.

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

docs/plans/2026-08-06-collision-fidelity-campaign.md

@@ -1,7 +1,13 @@
 # Campaign S — collision shape & response fidelity
 
 **Opened:** 2026-08-06, immediately after #333/#337 closed (`ea83b043`).
-**Status:** PLANNED, not started.
+**Status:** IN FLIGHT — overnight session 2026-08-07 ledger:
+S1A (AP-157) closed by measurement, no code · S1B contract ready, not
+implemented · S2 contract ready, not implemented · S3 CANCELLED (planned on a
+misreading — see its section) · S4 half-landed (AD-65 shipped; AD-66 withheld
+behind #341's measurement anomaly; AD-69 filed) · S5 closed (fix predated the
+campaign; zombie register row) · S6 unstarted · #330 hoist landed, wiring
+withheld with a seven-point scope map · #32/#338 pre-work both closed.
 **Scope:** the twelve remaining collision-domain items — five shape/membership
 divergences, three resolution-math divergences, two undecodable-math rows, and
 three open bugs.

docs/plans/2026-08-07-morning-gate-checklist.md

@@ -1,7 +1,8 @@
 # Morning gate — 2026-08-07 (one sitting)
 
-**Status: DRAFT — the overnight session updates this as work lands. Do not
-run it until this banner says READY.**
+**Status: READY — pending only the AD-65 review verdict and final commit,
+which the session lead completes before launch. Launch happens when you say
+go, not before.**
 
 Everything below folds the deferred visual gates into one sitting, ordered so
 travel between sites doubles as #339 reproduction attempts. Launch is
@@ -37,13 +38,38 @@ now part of every capture.
   then-active AD-56 row. Both corruptions fixed; the class is now a memory
   rule. No feel gate owed for S5.
 
-## 2. The sitting
+## 2. The sitting — ONE row
 
 | # | What | Where / how | Pass looks like |
 |---|---|---|---|
-| G1 | *(placeholder — filled in by the overnight landings: #330 is
-  automated-gate-only and needs no eyes; S1/S2/S3/S4/S5 rows appear here
-  exactly as far as the night got)* | | |
+| G1 | **S4 / AD-65 — downhill slope feel.** The away-from-plane response now
+  snaps to the surface (XY preserved) instead of projecting (XY shrunk by
+  cos²θ — 25% at 30°, 50% at 45°). | Run DOWN a long slope (the Rithwic
+  descent works), then across it diagonally; jump down-slope and land
+  running. | Downhill ground speed feels like retail — no "wading" slowdown
+  on descents; no new stutter or floatiness; landings keep momentum
+  downhill. |
+
+That is the whole sitting: **one slope run, ~3 minutes.** Everything else
+either closed with no gate owed or was deliberately withheld (below).
+
+## 2.5 Withheld / deferred overnight — nothing to test, decisions recorded
+
+- **AD-66 (the push-out's bare radius) — WITHHELD, issue #341.** The port is
+  byte-proven twice over, but the landing produced a measurement that
+  contradicted itself (same binaries, opposite outcomes flipping with test
+  assert shape). Parked behind an instrumentation plan rather than guessed
+  at. AD-69 filed alongside: the same block misses retail's seam-frame
+  correction.
+- **#330 headless collision — wiring withheld, hoist landed.** Dual review
+  converged on a real dependency the contract missed: headless has no
+  remote-motion tick, so spawn-registered shadows would freeze into phantom
+  obstacles. The issue now carries the full seven-point scope map.
+- **S1B (indoor box-admit) and S2 (static sphere emission)** — contracts
+  written and committed, not implemented; next session picks them up
+  directly.
+- **S3 — cancelled**: planned on a misreading; open doors are ethereal, so
+  AP-84's approximation is behaviourally equivalent. The register was right.
 
 ## 3. Free riders during travel