fix(physics): S1B — indoor cell membership admits on the part BOX, as retail does (#335, AP-159 narrowed)

CellTransit.FindTransitCellsBox ports CEnvCell::find_transit_cells'
part-array overload @0x0052cae0 line-for-line: per-portal x per-part
order, the sphere cheap-reject at F_EPSILON+radius, the box admit whose
"Straddle or crossing-side" rule is exactly retail's `eax != side` under
the PDB Sidedness enum, leads-outside placed AFTER the admit, the
unconditional unloaded-neighbour hint without the sphere overload's
re-test, the destination box_intersects_cell gate with its deliberate
no-break, and add_all_outside_cells after the loop. The box-vs-cell BSP
traversal lands in BOTH representations behind the flat-authoritative
dispatcher with a graph referee whose 20,000 installed comparisons are
pinned by assertion (review F5), zero mismatch.

Dual Opus review: PASS on both lenses. The mandatory D0 pseudocode pass
caught that the contract's own supplementary note misattributed the box
block to the sphere overload — it belongs to a SECOND
check_building_transit overload @0x0052c680, whose portal-side
convention is INVERTED and whose admit differs; the pseudocode doc now
records that trap plus two byte confirmations made at review:
which_side @0x00444720 is strictly > eps for POSITIVE, and
intersect_box's in-plane early exit returns CROSSING(3)
(jp @0x005aa1bc -> mov eax,3), settling review items b1/b2 for the
future bridge porter. The bridge itself stays unported as AP-159's
explicit remainder.

The review also retired #335's severity premise honestly: "over-
inclusive only, never a missed one" is wrong at production shape ratios,
where the box (whole-vertex AABB) legitimately exceeds the sphere
(physics-polygon root sphere). Measured, both populations: rigged
(box << sphere) — 1,520 placements, 978 cells removed, 0 added;
production-ratio (box >= sphere) — 950 placements, 20 removed, 1 ADDED
through the loaded-neighbour gate, which is retail's direction, not a
defect. The no-op guard (review F4) asserts removal is nonzero so an
unwired admit cannot pass silently.

Process note: the implementer authored against this session's worktree
at bec5c69d, 25 commits stale — the recorded worktree-base class. All
six files were byte-identical between bases, the diff transplanted
losslessly, and every verdict-bearing run (referee, direction sweeps,
this clean-room) was re-executed on current main. S2's uncommitted
phase-1 edits were stashed for this landing so the suite verdicts
exactly one changeset.

Also untracks 341-slope-capture.jsonl (an accidental add) and
gitignores it.

Clean-room suite: 11,248 passed / 6 skipped / 0 failed.

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

docs/ISSUES.md

@@ -593,7 +593,21 @@ Two additions close that:
 
 ## #335 — The INDOOR half of retail's part-array `find_transit_cells` is not ported: an EnvCell neighbour is admitted on a SPHERE test where retail uses a BOX
 
-**Status:** OPEN
+**Status:** CLOSED 2026-08-07 (Campaign S S1B). The indoor part-array arm is
+ported (`CellTransit.FindTransitCellsBox`), dual-reviewed PASS, sabotage-
+verified, with the box-vs-cell BSP traversal in both representations under a
+pinned 20,000-comparison installed referee. **The severity line below
+("over-inclusive only... never a missed one") is RETIRED with the port:** at
+production shape ratios the box legitimately exceeds the sphere (whole-vertex
+AABB vs physics-polygon root sphere), and the measured sweep shows the
+loaded-neighbour gate ADDING a cell the sphere test missed (1 in 950
+production-ratio placements) — retail-correct in both directions. Remainders
+(building bridge with its inverted portal-side convention, both its traps
+byte-settled; the one-ULP WhichSide tie) live in the narrowed AP-159 row.
+
+**Original entry:**
+
+**Status (original):** OPEN
 **Severity:** low. Over-inclusive only — extra broadphase candidates indoors, never a missed one. The opposite direction (the outdoor half) was #334 and is closed.
 **Filed:** 2026-08-06, at the #334 fix.
 **Component:** physics / cell membership