docs: close the AD-10 review findings — AD-65's magnitude was half the truth

Both AD-10 review lenses PASS; the deletion stands. These are the findings
they raised. One production file touched, comment-only.

AD-65 WAS UNDERSTATED BY HALF, and it is the finding that matters. The row
states the factor as cos^2(theta) and then quantified 1-cos(theta): "13% at
30 degrees, 29% at 45". The correct figures are 25% and 50%. This is not
algebra alone — #331's probe in the same push measures 0.0735 m travelled for
a 0.1 m request at 30.96 degrees, i.e. 26.5% short, which is exactly
cos^2(30.96). AD-65 is a LEAD for #269's slope-slide residual; at the
understated magnitude it reads as marginal and could have been dismissed. At
50% short at 45 degrees it is a serious candidate. I repeated the wrong figure
in conversation before the review caught it.

"VERBATIM/FAITHFUL PORT" of Transition.AdjustOffset was asserted in five
places and was false as of the very next commit, which filed AD-65 and AD-66
against that same function. Corrected to "structurally exact, with exactly two
filed divergences" in the register row and the production doc comment.

RECORDED, and it favours the change: the redundancy measurement is CONTINGENT
on AD-65 — the two mechanisms agree today partly because both under-travel
downhill. That makes this deletion a PREREQUISITE for fixing AD-65 rather than
merely compatible with it; had the projection survived, correcting
AdjustOffset would have re-introduced a disagreement between two live
projections. The record claimed no such thing and should have.

UNTESTED AXIS recorded: the contract's T2 — its mandatory wrong-plane-versus-
right-plane discriminator — was dropped without record, breaching the
contract's own clause requiring exactly that to be written down. The
consequence is precise: the deletion is measured, but the change's only
claimed BENEFIT (a walkable non-terrain surface now gets the committed contact
plane instead of terrain far below) has zero automated coverage and rests on
source reasoning. Stated in the row rather than left implied.

#331 SEVERITY RAISED from UNKNOWN — the discriminator is known and it is not
the fixture. With `body: null` the same uphill sweep climbs (ok=True, moved
(0, -0.0999, +0.060)); with a body supplied it returns ok=False and zero
movement, under a call profile identical to the local player's
(IsPlayer|EdgeSlide + the human two-sphere Setup). A diagonal request keeps
cross-slope X and zeroes only up-slope Y, and it fires on a 1.1 degree ramp.
So "confined to the synthetic fixture" is no longer the comfortable default:
the failing call shape is the shape production uses. Nothing in the suite
asserts uphill progress on a walkable slope, which is why it was invisible —
the test that found it passed vacuously, because the body never moved.

Also: malformed XML doc on ComposeOffset (duplicate </summary> swallowed the
retirement note from tooling) fixed; the placement-cutover plan's item 5 and
its stale "After C5" line now record AP-22 and AD-10 as retired.

Core builds clean.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

docs/plans/2026-08-02-placement-cutover.md

@@ -84,6 +84,17 @@ Remaining campaign work, in order:
 5. Delete the superseded paths, retire AP-1/AD-1/AP-131 and AD-60's legacy
    half only when the code proves they are gone, then complete AP-22 and
    AD-10 and close the campaign ledger.
+   **DONE except the ledger close, 2026-08-05/06.** AP-1/AD-1 retired at C5a
+   (`6921a027`); AP-131 and AD-60's legacy half at C5b (`735f0a72`); **AP-22**
+   retired at `bc4679cd` (all three invented-cylinder copies deleted — the row
+   listed one; reachability proved zero over all 5,935 installed Setups by four
+   independent decoders); **AD-10** retired by deletion at `886333a2` (its
+   stated justification was false at HEAD — remotes DO run the sweep, so the
+   projection was an extra non-retail layer, measured bit-identical when
+   removed). Both dual-reviewed, both lenses PASS. Remaining: C5c's gates and
+   the ledger close. Two new divergences were filed out of AD-10's work
+   (AD-65, AD-66) and two issues (#331 uphill-resolve blockage, #332 headless
+   remote dead-reckoning).
 
 **Inputs (read in order):**
 1. [`2026-08-02-runtime-continuation-executor-handoff.md`](../research/2026-08-02-runtime-continuation-executor-handoff.md)
@@ -627,6 +638,8 @@ same commit) → docs/handoff commit. No workarounds; no fused slices.
   include a first-login stop, because login shares the same barrier and its
   gate widened too.
 
+After C5: ~~AP-22~~ (RETIRED 2026-08-06, bc4679cd) and ~~AD-10~~ (RETIRED
+2026-08-06 by deletion, 886333a2) are both DONE. Historical text follows.
 After C5: AP-22 (authored collision shapes), then AD-10 (remote
 contact-plane projection), then the campaign's final matrix and ledger
 closeout; vendor Slice 5 resumes.