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.Runtime/Gameplay/PlayerMovementController.cs

@@ -163,6 +163,21 @@ public sealed class PlayerMovementController
     /// </summary>
     public float StepDownHeight { get; set; } = 0.4f;
 
+    /// <summary>
+    /// TS-46 (2026-07-30): the player's own Setup ≤2-sphere list (dat
+    /// <c>CSphere</c> Origin+Radius), verbatim per retail
+    /// <c>CPhysicsObj::transition</c> (0x00512dc0) →
+    /// <c>SPHEREPATH::init_sphere</c> (0x0050c670). Set at world-entry by
+    /// <c>PlayerModeController.ApplyStepHeights</c> alongside
+    /// <see cref="StepUpHeight"/>/<see cref="StepDownHeight"/>. Default
+    /// (empty) falls back to <c>ResolveWithTransition</c>'s legacy
+    /// (0.48, 1.835) two-scalar capsule reconstruction — the human Setup
+    /// 0x02000001's authored spheres are (0,0,0.475) r=.48 and
+    /// (0,0,1.350) r=.48, a 5 mm improvement over the reconstruction's
+    /// (0,0,0.48) + (0,0,1.355).
+    /// </summary>
+    public System.Collections.Immutable.ImmutableArray<FlatCollisionSphere> SphereList { get; set; }
+
     /// <summary>
     /// Retail <c>CPhysicsObj::m_scale</c>. Grounded CSequence root
     /// displacement is multiplied by this value before PositionManager
@@ -1404,7 +1419,12 @@ public sealed class PlayerMovementController
                     isOnGround: previousOnWalkable,
                     body: _body,
                     moverFlags: ObjectInfoState.IsPlayer | ObjectInfoState.EdgeSlide,
-                    movingEntityId: LocalEntityId);
+                    movingEntityId: LocalEntityId,
+                    // TS-46: the player's own Setup sphere list, scaled by
+                    // ObjectScale. Empty falls back to the 0.48/1.835
+                    // reconstruction above.
+                    sphereList: SphereList,
+                    sphereScale: ObjectScale);
                 _body.CommitTransitionPosition(resolved.CellId, resolved.Position);
                 PhysicsObjUpdate.CommitSetPositionTransition(
                     _body,
@@ -1849,7 +1869,14 @@ public sealed class PlayerMovementController
                 // when the local player entity spawns (or stays 0 in tests, in
                 // which case there's no registered ShadowEntry to collide with
                 // anyway).
-                movingEntityId: LocalEntityId);
+                movingEntityId: LocalEntityId,
+                // TS-46 (2026-07-30): the player's own Setup sphere list
+                // (0x02000001: (0,0,0.475) r=.48 + (0,0,1.350) r=.48),
+                // scaled by ObjectScale. Empty (unset/no Setup resolved yet)
+                // falls back to the sphereRadius/sphereHeight reconstruction
+                // above.
+                sphereList: SphereList,
+                sphereScale: ObjectScale);
 
             // L.4-diag (2026-04-30): trace position transitions so we can see
             // whether the body is actually moving frame-to-frame on the steep