fix #175: door BSP collision poses at the motion-table closed pose

The Facility Hub double door (Setup 0x02000C9D) embeds the player into
the visual panel from one side and blocks with a phantom slab on the
other: its Setup PLACEMENT frames pose the two panels AJAR (yaw
-150/-30 deg, 0.44 m behind the doorway plane — dat-confirmed by the
Issue175 inspection) while the rendered door poses them CLOSED from
the wire-supplied motion table via the sequencer. ShadowShapeBuilder
read placement frames, so the 1.66x0.29x2.95 m physics slabs
registered at the ajar pose. Retail tests each part's LIVE
CPhysicsPart pose — for an idle door, the motion table's default
(closed) state.

Fix: ShadowShapeBuilder.FromSetup gains partPoseOverride (BSP part
shapes only); RegisterServerEntityCollision derives it from the spawn
MotionTableId via GameWindow.MotionTableDefaultPose (default style ->
first cycle -> LowFrame part frames). Null/short poses fall back
per-part to placement frames — table-less entities and landblock
statics unchanged. One-shot snapshot vs retail's per-frame live pose
is register row AP-84 (equivalent for the door lifecycle: closed ==
default pose; open == ETHEREAL bypasses collision, #150).

Pins: FromSetup_PartPoseOverride_ReplacesPlacementFrames /
_NoOverride_KeepsPlacementFrames / _ShortOverride_FallsBackPerPart.
Suites: Core 2539 / App 713 / UI 425 / Net 385 green.

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

docs/architecture/retail-divergence-register.md

@@ -179,6 +179,7 @@ accepted-divergence entries (#96, #49, #50).
 | AP-80 | **PlanFromVelocity survives for velocity-only NPC cycles** (M16): UpdatePosition-derived speed picks Ready/Walk/Run cycles for server-controlled creatures whose UMs never arrive (scripted-path NPCs); retail derives every cycle from motion messages through the motion tables (R4-V4 note; pre-existing mechanism, row added per the V4 plan) | `src/AcDream.Core/Physics/ServerControlledLocomotion.cs` (`PlanFromVelocity`); consumer `GameWindow.ApplyServerControlledVelocityCycle` | Some ACE entities move by position updates alone — without this, they slide in T-pose; constants (StopSpeed 0.2, RunThreshold 1.25) tuned against live ACE traffic | Cycle-pick thresholds are acdream inventions — a creature intended to walk fast may show run legs near the threshold | retire in R6 (root motion + full per-tick order) |
 | AP-81 | **Remote-DR gravity toggled via the Gravity STATE bit**: the jump handler sets `Body.State \|= Gravity` at VectorUpdate and both landing blocks clear it after `HitGround()`; retail keeps GRAVITY set for the object's whole life and gates gravity ACCELERATION on the Contact transient (`calc_acceleration`) (pre-existing K-fix9/K-fix15 mechanism, row added during #161 — which also fixed the ordering so `Motion.HitGround()`'s verbatim `state&0x400` gate runs BEFORE the clear) | `src/AcDream.App/Rendering/GameWindow.cs` (VectorUpdate jump handler + the two landing blocks) | The DR tick integrates gravity only for airborne remotes; the flag dance delivers exactly that without porting the full contact-gated `calc_acceleration` chain; the #161 ordering fix keeps the retail HitGround contract satisfied | Any NEW call into `Motion.HitGround`/`LeaveGround` placed after the clear silently no-ops on the gravity gate (the #161 leg-2 class); grounded remotes carry a non-retail state word (probes comparing state bits vs retail mislead) | `CPhysicsObj::calc_acceleration` (contact-gated); `set_on_walkable` 0x00511310; retire in R6 (contact-gated accel + persistent GRAVITY) |
 | AP-82 | **StickyManager deep-overlap back-off sign pin**: when the stick-gap overlap exceeds one tick's step (`speed×quantum < \|dist\|`, `dist < 0`), acdream applies `delta = −(speed×quantum)` (rate-limited back-off); ACE's literal port keeps `+delta` there — a runaway that steers INTO the target with equilibrium at centers-coincident. The BN mush (0x00555554-0x00555597) is unreadable on exactly this compare; the pin is refuted-by-evidence against ACE-literal: #171 gate-3 probe showed 1661 deep-overlap ticks all steering inward (monsters converged to centerDist≈0 — "monster inside the player") while retail side-by-side on the same ACE shows separation. ACE servers essentially never reach the branch (quantum ≥1/30 → threshold ~1 m; render-rate quanta → ~0.13 m) | `src/AcDream.Core/Physics/Motion/StickyManager.cs` (`AdjustOffset` delta clamp; conformance `StickyManagerTests.AdjustOffset_DeepOverlap_BacksOff_RateLimited`) | Minimal interpretation consistent with the mush structure AND observed retail; identical to ACE-literal in every shallow/outside case | If retail's true deep-overlap behavior differs (e.g. no movement at all), our back-off rate diverges in that rare state; verify via cdb `StickyManager::adjust_offset` trace with a forced overlap when convenient | `StickyManager::adjust_offset` 0x00555430 (x87 mush); ACE StickyManager.cs:117-121 (the literal branch this pin overrides) |
+| AP-84 | **BSP shadow-shape part poses = motion-table default-state frame snapshot at registration, not retail's live CPhysicsPart pose** (#175): server entities with a wire MotionTableId register their BSP part shapes at the default style's first-cycle LowFrame pose (the closed pose for doors — `GameWindow.MotionTableDefaultPose`); retail collision reads each part's CURRENT pose every test. Equivalent for the door lifecycle (closed = default pose; open = ETHEREAL bypasses collision entirely, #150) and for idle statics | `src/AcDream.App/Rendering/GameWindow.cs` (`MotionTableDefaultPose` + the RegisterServerEntityCollision override); `src/AcDream.Core/Physics/ShadowShapeBuilder.cs` (`partPoseOverride`) | Registration is one-shot in acdream (retail re-poses parts per frame); the default-state pose is the correct idle pose and the only non-ethereal pose doors ever collide in | An entity whose server-driven motion state materially MOVES a BSP-bearing part while NON-ethereal would collide at the stale default pose (no known case — doors are the dominant BSP-part weenies); revisit if animated non-ethereal BSP movers appear | `CPhysicsPart` live pose (see #150 notes); motion-table default state = CPartArray init; ShadowShapeBuilder placement-frame fallback for table-less entities |
 | AP-83 | **CylCollideWithPoint PerfectClip TOI sub-branches decoded via ACE, not the binary**: the CCylSphere family port (2026-07-05, retires AP-6) reads `collide_with_point`'s PerfectClip time-of-impact math (0x0053adb6+) from ACE `CylSphere.CollideWithPoint` because the BN x87 mush is unreadable there; two ACE-verbatim quirks ported as-is (`movement.Z + radius` in the not-definite ascending case; `GlobalCurrCenter[0]` used even for head-sphere hits — the latter matches the raw decomp read). NOT exercised in M1.5: no mover sets PerfectClip (players never do; the non-PerfectClip path — SetCollisionNormal + Collided — is decomp-verified). Separately, the grounded head-sphere slide passes the HEAD disp per retail 0x0053b843 where ACE passes the foot disp — retail wins (ACE bug, not copied) | `src/AcDream.Core/Physics/TransitionTypes.cs` (`CylCollideWithPoint`; pseudocode doc `docs/research/2026-07-05-ccylsphere-collision-family-pseudocode.md` §7-8) | The load-bearing paths (non-PerfectClip Collided; the family's step-up/step-down/land) are decomp-verified; the TOI tail is dead code until missiles arm PerfectClip | If missiles (F.3) arm PerfectClip, the two ACE quirks may diverge from retail — clip-through or wrong deflection on cylinder targets; re-decompile 0x0053acb0 in Ghidra before shipping missiles | `CCylSphere::collide_with_point` 0x0053acb0 (pc:324173, x87 mush from 0x0053adb6); ACE CylSphere.cs `CollideWithPoint` |
 
 ## 4. Temporary stopgap (TS) — 39 rows (TS-37 is a retired-row historical note, not an active count; TS-39 retired R5-V3 — sticky seams bound to the ported PositionManager/StickyManager, radii threaded)