test(vehicle): park the Chaos pawn and give the physics its own task

The pawn was found again after a cleanup removed its staging, and the diagnostic answers the
zero-wheel question with a bigger one: with the pawn present the actor is launched to Z 1993 cm - 18 m
above the ground it stands at 150 - and still reports 0 wheels.

  GigLine vehicle diag: mesh=1 simulating=1 physasset=yes setups=4 wheels=0
  GigLine vehicle: settled at Z 1993 cm, simulating=1

Wheels are only created inside CreateVehicle() when the physics state produced a vehicle, so the
chassis body is the suspect rather than the wheel setup: PA_Vehicle_Sedan has one box on the root bone,
and a body that starts intersecting geometry is the usual reason a vehicle pawn launches itself.

Parked rather than shipped: the pawn is not staged, the visible car stays as panels, and the physics is
'Vehicle physics - Chaos rig' in TODO.md with the evidence and three concrete steps. The demo no longer
carries an 18 m flying car in its captures.

TODO.md

@@ -9,6 +9,26 @@ Actionable task list for this project. This file is the single, central place fo
 - When all steps in a version section are done: write a `CHANGELOG.md` entry, then remove the version section from this file.
 - Release gate: a version is tagged only on the owner's explicit go-ahead once its release checks pass, not automatically when the checkboxes close.
 
+## Vehicle physics — Chaos rig (own task, from `0.3.0`)
+
+Split out of `0.3.0` because it is a physics problem, not an asset one. **The Chaos pawn is parked**: with it staged the actor is launched to **Z 1993 cm** (18 m up) and reports **0 wheels**, so it litters the demo without being drivable. The visible car is the plain panel set, which looks right and is what the review shots show.
+
+### Evidence
+
+```
+GigLine vehicle: 0 wheel objects once physics exists
+GigLine vehicle: ground at Z 150 cm, actor 1993 cm, height above ground 1843 cm
+GigLine vehicle: settled at Z 1993 cm, simulating=1, speed=0 cm/s
+```
+
+Wheels are created in `CreateVehicle()` only when the physics state produced a vehicle, so the chassis body itself is the suspect: `PA_Vehicle_Sedan` carries one box on the `root` bone, and the skeletal mesh is `SK_Vehicle_Sedan`. A vehicle pawn that launches itself upward usually has a body that starts intersecting geometry, or a physics asset whose body sits at the origin rather than under the car.
+
+### Tasks
+
+- [ ] Give `SK_Vehicle_Sedan` a physics asset whose single chassis body matches the car's box and is positioned below the shell, then confirm the pawn settles on the road instead of launching.
+- [ ] Confirm `Wheels.Num()` becomes 4 once the vehicle is created; log it at the settle check.
+- [ ] Only then re-stage the pawn, re-add enter/exit and the driving route.
+
 ## Hero facade rework — from the ReviewMap review (own task)
 
 Split out of `0.3.0` on 2026-11-09 on the owner's instruction: the three hero-facade staging shots (`review-hero-facade-front`, `review-hero-facade-oblique`, `review-hero-portals`) were rejected as "rework needed to match reference", and that is asset work rather than vehicle work.