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.App/Physics/DeferredLiveEntityMotionRuntimeBindings.cs

@@ -1,6 +1,8 @@
+using System.Collections.Immutable;
 using AcDream.App.Physics;
 using AcDream.App.Rendering;
 using AcDream.Core.Net;
+using AcDream.Core.Physics;
 using AcDream.Core.Physics.Motion;
 using AcDream.Core.World;
 
@@ -14,6 +16,11 @@ namespace AcDream.App.Physics;
 internal interface ILiveEntityMotionRuntimeBindings
 {
     (float Radius, float Height) GetSetupCylinder(uint serverGuid, WorldEntity entity);
+
+    /// <summary>TS-46 sibling of <see cref="GetSetupCylinder"/> — see
+    /// <c>LiveEntityMotionRuntimeController.GetSetupMoverShape</c>.</summary>
+    (ImmutableArray<FlatCollisionSphere> Spheres, float Scale, float StepUpHeight, float StepDownHeight)
+        GetSetupMoverShape(uint serverGuid, WorldEntity entity);
     bool RouteServerMoveTo(
         MovementManager movement,
         uint cellId,
@@ -59,6 +66,10 @@ internal sealed class DeferredLiveEntityMotionRuntimeBindings
         uint serverGuid,
         WorldEntity entity) => Target.GetSetupCylinder(serverGuid, entity);
 
+    public (ImmutableArray<FlatCollisionSphere> Spheres, float Scale, float StepUpHeight, float StepDownHeight)
+        GetSetupMoverShape(uint serverGuid, WorldEntity entity) =>
+        Target.GetSetupMoverShape(serverGuid, entity);
+
     public bool RouteServerMoveTo(
         MovementManager movement,
         uint cellId,