fix(physics): restore retail edge-response ordering

docs/research/2026-07-30-response-layer-edge-family-pseudocode.md

@@ -1,7 +1,7 @@
 # P2 — Collision response-layer edge family: port-ready pseudocode
 
-**Status: RESEARCH PASS COMPLETE (2026-07-30); IMPLEMENTATION PASS PARTIAL
-(2026-07-30).** Originally a research-only doc for Campaign P Slice P2
+**Status: RESEARCH PASS COMPLETE (2026-07-30); RETAIL RESPONSE ORDER PORTED
+(2026-07-31).** Originally a research-only doc for Campaign P Slice P2
 (`docs/plans/2026-07-29-physics-parity-campaign.md` §P2); a same-day
 implementation session landed TS-1's retirement and AP-7's fix, attempted
 TS-4 per this doc's own §6 Step 3 fixture-first order, reproduced the
@@ -24,7 +24,10 @@ unreachable from Path 6's unconditional `SetCollide`, which returns
 `Adjusted` without repositioning the sphere) and what a future attempt
 needs to check first; #116 remains a genuine oracle-first research item
 needing live cdb/Ghidra, not an implementation item (see §5). Read §6 (port
-order) before starting further implementation on this family.
+order) before starting further implementation on this family. Campaign P
+Slice 1B subsequently performed that fresh `transitional_insert` read and
+removed AP-3, AP-4, AD-53, and AD-54; the exact closeout and controls are in
+§8. TS-4 remains deliberately unchanged.
 
 Every claim below is tagged **FACT** (grep/read-verified against the
 named-retail decomp, the register, ISSUES.md, or current acdream source
@@ -72,12 +75,11 @@ These bind the P2 implementer. Do not re-attempt any of these shapes.
    once already (2026-06-12) for the EPSILON-vs-EpsilonSq bug; Ghidra MCP
    is DOWN for this research pass — mark any residual x87-ambiguous claim
    Ghidra-verify, cite ACE as the fallback tiebreaker, do not silently guess.
-9. **AP-4 (CliffSlide check moved before retail's Branch-1 gate)** is a
-   live, load-bearing reordering compensating for acdream's incomplete
-   OnWalkable bookkeeping — touches the same code region as TS-1. Do not
-   revert AP-4's reordering without re-verifying OnWalkable is complete;
-   read AP-4's full row before changing `TransitionTypes.cs:1316` control
-   flow.
+9. **SUPERSEDED 2026-07-31 by Campaign P Slice 1B.** AP-4's CliffSlide-first
+   compensation was removed only after the complete retail
+   `transitional_insert`/`edge_slide` order was read and branch-order plus
+   graph/flat multi-frame roof/ledge controls passed. Do not reintroduce the
+   compensation; see §8 and the retired AP-4 row.
 10. **TS-46 (two-scalar sphere reconstruction) is OUT OF SCOPE for P2**
     (it's P3) but shares files (`TransitionTypes.cs` `InitPath`) — do not
     fold TS-46 sphere-list work into a P2 commit.
@@ -1066,3 +1068,46 @@ it blocks.
    behavior."
 
 ---
+
+## 8. Campaign P Slice 1B closeout — exact response ordering (2026-07-31)
+
+The follow-up read used the complete named-retail bodies, not the earlier
+excerpt summaries:
+
+- `CTransition::transitional_insert` at `0x0050B6F0`
+  (pseudo-C:273137 onward) returns `OK_TS` as soon as
+  `contact_plane_valid != 0`. Only an invalid contact reaches the ordinary
+  StepDown tail, whose remaining gates are Contact,
+  `!sphere_path.step_down`, a non-null check cell, and ObjectInfo.StepDown.
+- Its StepDown schedule is asymmetric by authored sphere count. For a
+  one-sphere mover whose requested height exceeds the foot diameter, retail
+  clamps the probe to half the foot radius and performs one probe. Otherwise
+  a request within the diameter probes once; an over-diameter request on a
+  two-sphere mover is halved and probes twice in sequence.
+- `CTransition::edge_slide` at `0x0050B3D0`
+  (pseudo-C:273001-273090) runs `!OnWalkable || !EdgeSlide` restore-and-OK
+  before its steep-contact CliffSlide branch. Any stored walkable polygon
+  routes to PrecipiceSlide without a steepness test.
+- `CTransition::cliff_slide` at `0x0050A6D0`
+  (pseudo-C:272397 onward) crosses the supplied contact normal only with
+  `collision_info.last_known_contact_plane.N`. It has no remembered-walkable
+  or world-up substitute. A default, invalid, parallel, or otherwise
+  degenerate cross naturally returns `OK_TS` through the retail normalization
+  guard.
+
+`TransitionTypes.cs` now follows that order exactly. AP-3, AP-4, AD-53, and
+AD-54 are retired together. The implementation deliberately preserves the
+existing ordinary-tail `runPlacement: false` choice and does not alter TS-4's
+Path-6 steep-polygon shortcut.
+
+`RetailEdgeResponseOrderingTests` pins every distinguishing branch: valid
+steep-contact early return, the one/two-sphere probe schedule,
+not-OnWalkable-before-CliffSlide, last-known-only source selection, degenerate
+last-known handling, and stored-steep-walkable-to-Precipice routing. It also
+runs multi-frame steep-roof and flat-roof-edge controls through both parsed
+graph and prepared-flat collision traversal, requires exact trace parity, and
+rejects a greater-than-15-tick frozen streak. The earlier dedicated
+`Ts4SteepRoofWedgeCaptureTests` remains green, so retiring these four
+compensations did not require weakening or deleting the TS-4 control.
+
+---