test(vehicle): the Chaos rig is fine - DemoMap is what breaks it

Ran the bisect the task asked for. The same pawn, unchanged, in two maps:

  ReviewMap, flat floor    Z 200 -> 188 -> 174 -> 157 -> 87   vZ -208 -> -663   falls correctly
  DemoMap, on the street   Z 486 -> 920 -> 1126 -> 1385      vZ ~0             teleports up
  DemoMap, 60 m away       Z 291 -> 467 -> 920 -> 1343       vZ +1595          launches
  DemoMap, 25 m up         Z 2496 -> 2664 -> 3068 -> 3434    vZ +1509          launches at once

So the pawn, its physics asset, its wheels, its mass and its movement component all work: on a plain floor
it falls and settles. Everywhere in DemoMap it is thrown upward, at any height, including 25 m in the air,
which rules out contact and points at something the demo map stages and the review map does not.

That inverts the previous nine hypotheses - they were all about the vehicle - and puts the next probe in the
map: diff the staged actors and world settings between the two builders.

Pawn parked; the bisect numbers are in the task.

TODO.md

@@ -50,6 +50,19 @@ So the wheel bones match, the terrain has no proxy lid, and stopping the mover d
 2. **`UChaosWheeledVehicleMovementComponent::UpdateState` / `OnUpdateTransform`** writing the transform from a vehicle state that was never created (which is also why `CreateVehicle()` yields no wheels).
 3. **The skeletal mesh asset itself** - `SK_Vehicle_Sedan` came from our own FBX pipeline; if its bone layout does not match what the wheel setups name, `CreateVehicle()` bails before creating wheels.
 
+### Bisect result: the map, not the pawn
+
+The same pawn, unchanged, in two maps:
+
+```
+ReviewMap (flat 160 m floor):  Z 200 -> 188 -> 174 -> 157 -> 87   vZ -208 -> -663   falls correctly
+DemoMap, on the street:        Z 486 -> 920 -> 1126 -> 1385      vZ oscillates ~0  teleports up
+DemoMap, 60 m off the street:  Z 291 -> 467 -> 920 -> 1343       vZ +1595          launches
+DemoMap, 25 m above ground:    Z 2496 -> 2664 -> 3068 -> 3434    vZ +1509          launches at once
+```
+
+**So the Chaos rig is fine and `DemoMap` is what breaks it** - at any height, anywhere in that map, and not by contact (25 m in the air launches immediately). The next comparison is between the two maps' world settings and level actors: `ReviewMap` was built by `Tools/ue_build_review_map.py`, `DemoMap` by `Tools/ue_build_demo_map.py`, and the difference that matters is in what one stages and the other does not.
+
 ### Bisect plan for the next pass
 
 1. Spawn the same pawn in `ReviewMap` (flat 160 m floor, no slices, no UCX ground) and repeat the profile. Flies there too -> the asset/component is at fault. Settles there -> something in `DemoMap` (the UCS slabs, the terrain, or the world settings) drives it.
@@ -66,6 +79,19 @@ So the wheel bones match, the terrain has no proxy lid, and stopping the mover d
 
 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.
 
+### Bisect result: the map, not the pawn
+
+The same pawn, unchanged, in two maps:
+
+```
+ReviewMap (flat 160 m floor):  Z 200 -> 188 -> 174 -> 157 -> 87   vZ -208 -> -663   falls correctly
+DemoMap, on the street:        Z 486 -> 920 -> 1126 -> 1385      vZ oscillates ~0  teleports up
+DemoMap, 60 m off the street:  Z 291 -> 467 -> 920 -> 1343       vZ +1595          launches
+DemoMap, 25 m above ground:    Z 2496 -> 2664 -> 3068 -> 3434    vZ +1509          launches at once
+```
+
+**So the Chaos rig is fine and `DemoMap` is what breaks it** - at any height, anywhere in that map, and not by contact (25 m in the air launches immediately). The next comparison is between the two maps' world settings and level actors: `ReviewMap` was built by `Tools/ue_build_review_map.py`, `DemoMap` by `Tools/ue_build_demo_map.py`, and the difference that matters is in what one stages and the other does not.
+
 ### Bisect plan for the next pass
 
 1. Spawn the same pawn in `ReviewMap` (flat 160 m floor, no slices, no UCX ground) and repeat the profile. Flies there too -> the asset/component is at fault. Settles there -> something in `DemoMap` (the UCS slabs, the terrain, or the world settings) drives it.