fix(physics): TS-46 - seed the sweep from the Setup's own sphere list

Campaign P Slice P3 item 1. Retail CPhysicsObj::transition (0x00512dc0)
seeds the collision sweep from CPartArray::GetSphere (the Setup's own
<=2-sphere list, each origin+radius scaled by m_scale) via
SPHEREPATH::init_sphere (0x0050c670) -- not from a symmetric two-scalar
(radius, height) capsule reconstruction. The human Setup 0x02000001's
authored spheres are (0,0,0.475) r=.48 and (0,0,1.350) r=.48; the old
reconstruction from (0.48, 1.835) produced (0,0,0.48) + (0,0,1.355), a
5 mm head-center offset the TS-46 register row documented as a residual.

Port:
- SpherePath.InitPath gains a sphere-list overload (ImmutableArray<
  FlatCollisionSphere>, scale) sharing a new InitPathCore with the
  existing (radius, height) overload, which is now the degenerate
  2-scalar case of the same code -- byte-for-byte unchanged, so every
  captured-fixture replay (CellarUpTrajectoryReplayTests,
  DoorBugTrajectoryReplayTests, CellarLipWedgeTests) keeps passing
  unmodified.
- PhysicsEngine.ResolveWithTransition gains optional sphereList/
  sphereScale parameters; empty/default preserves the legacy scalar
  path for every pre-existing caller.
- LiveEntityMotionRuntimeController.GetSetupMoverShape is a new sibling
  of GetSetupCylinder (left untouched) that resolves the Setup's own
  sphere list plus Setup-derived step-up/step-down
  (CPartArray::GetStepUpHeight/GetStepDownHeight, 0x005180d0/0x005180f0,
  x ObjScale, 0.4 m fallback matching the pre-existing literal).
- Threaded through PlayerMovementController (both resolve call sites,
  new SphereList property set by PlayerModeController.ApplyStepHeights
  and the Headless world projection), RuntimeRemotePhysicsUpdater
  (Tick + TickHidden), and RuntimeOrdinaryPhysicsUpdater.TryBegin.
  Remote/ordinary step heights are now Setup-derived instead of a
  hardcoded 0.4f literal. Projectile and camera-probe sweeps are
  untouched (already single-sphere-exact).
- PlayerModeController.ApplyStepHeights also now applies the x ObjScale
  multiply to the player's own step heights (previously only the
  remote/ordinary paths did), closing an adjacent gap the P3 research
  flagged.

Ts46SphereListConformanceTests proves the sphere-list overload sees the
exact dat spheres (not the reconstruction), that the scalar overload is
unchanged, and that ResolveWithTransition's sphereList parameter
actually drives the sweep (a decoy-scalar control pair using a
head-height obstacle sphere).

Register: TS-46 retired (both residuals it named are closed); header
count corrected to 40 active TS rows.

dotnet build + dotnet test (Core.Tests 3991/2 skip, Runtime.Tests
425/0, App.Tests 3968/3 skip, complete solution build) all green.

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

src/AcDream.Core/Physics/PhysicsEngine.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Collections.Immutable;
 using System.Numerics;
 
 namespace AcDream.Core.Physics;
@@ -1093,7 +1094,17 @@ public sealed class PhysicsEngine
         Vector3? localSphereOrigin = null,
         Quaternion? beginOrientation = null,
         Quaternion? endOrientation = null,
-        uint designatedTargetId = 0)
+        uint designatedTargetId = 0,
+        // TS-46 (2026-07-30): the mover's own Setup ≤2-sphere list (retail
+        // CPhysicsObj::transition 0x00512dc0 → SPHEREPATH::init_sphere
+        // 0x0050c670), scaled by sphereScale (the object's own m_scale /
+        // wire ObjScale) exactly as init_sphere applies it per-sphere.
+        // Default/empty preserves the legacy sphereRadius/sphereHeight
+        // two-scalar reconstruction below — every pre-existing caller
+        // (camera probe, projectiles, captured-fixture replays) that omits
+        // this parameter is byte-for-byte unaffected.
+        ImmutableArray<FlatCollisionSphere> sphereList = default,
+        float sphereScale = 1f)
     {
         // A6.P3 #98 (2026-05-23) live capture. Filtered to IsPlayer so NPC /
         // remote ResolveWithTransition calls don't pollute the capture. Snapshot
@@ -1185,15 +1196,33 @@ public sealed class PhysicsEngine
                 transition.CollisionInfo.SetSlidingNormal(body.SlidingNormal);
             }
 
-            transition.SpherePath.InitPath(
-                currentPos,
-                targetPos,
-                cellId,
-                sphereRadius,
-                sphereHeight,
-                localSphereOrigin,
-                beginOrientation,
-                endOrientation);
+            if (!sphereList.IsDefaultOrEmpty)
+            {
+                // TS-46: the Setup's verbatim sphere list, not the two-scalar
+                // capsule reconstruction. localSphereOrigin has no meaning
+                // here — every sphere already carries its own dat-authored
+                // origin.
+                transition.SpherePath.InitPath(
+                    currentPos,
+                    targetPos,
+                    cellId,
+                    sphereList,
+                    sphereScale,
+                    beginOrientation,
+                    endOrientation);
+            }
+            else
+            {
+                transition.SpherePath.InitPath(
+                    currentPos,
+                    targetPos,
+                    cellId,
+                    sphereRadius,
+                    sphereHeight,
+                    localSphereOrigin,
+                    beginOrientation,
+                    endOrientation);
+            }
 
             // #145: supply the carried cell-relative frame anchor to the outdoor
             // membership pick. body.Position - body.CellPosition.Frame.Origin is the TRUE