docs(vehicle): fresh probe data — the writer is the physics sim, asset pipeline ruled out

Rebuilt and re-ran the vehicle probe workflow:

- Control (no terrain) falls and settles (300 -> 78 cm).
- Terrain rises (313 -> 545 cm) with body velocity pinned to 0 and zero overlaps.
- Turning physics OFF at 3 s stops the rise, so the Chaos vehicle solver is
  teleporting the body (transform set directly, no velocity) - not an external
  SetActorLocation.
- 0 wheels in both runs, so the missing wheels are not the trigger; the terrain is
  what flips fall to rise.

Ruled out the asset pipeline with commandlets: the FBX, the imported
SK_Vehicle_Sedan (476x228x144 cm), the physics asset (452x205x40) and Terrain_DEM
(380x210 m) are all correct; the logged '1 cm bounds' is a stale component read,
not a bad mesh.

Next: bisect step 2 - a stock AWheeledVehiclePawn beside AGigLineVehicle in the
terrain probe map.

TODO.md

@@ -11,6 +11,8 @@ Actionable task list for this project. This file is the single, central place fo
 
 ## Toolchain — end-to-end asset check (done 2026-11-10)
 
+> [!IMPORTANT] Plan for 0.3.1 before other patches
+
 The chain that answers "does the asset look right in both the staging map and the game map" is now one command: `python3 Tools/review/e2e_asset_check.py`. It renders the Blender source, empties both maps, runs both builders, captures, judges with two models, and regenerates `Screenshots/README.md`. Last full run: **PASS on all six steps** (empty maps 9 s, demo build 10 s, review build 9 s, captures 80 s, judge 388 s).
 
 - [x] Group the sixty tools by sandbox: `Tools/unreal/`, `Tools/blender/`, `Tools/review/`, `Tools/gen/`, `Tools/input/`, with the layout documented in `Tools/README.md`.
@@ -133,6 +135,8 @@ Deferred rather than guessed. What a fresh session needs:
 
 Two facts that matter more than the hypothesis list above: on `ReviewMap`'s flat floor the **same pawn falls correctly** (Z 200 -> 87, vZ -663), and in `DemoMap` it teleports upward at any height - including 25 m in the air - with the transform written directly (clamping velocity to zero every frame does not stop it) while the body reports a near-zero velocity. Disabling the movement component's tick changes nothing; there are zero overlaps; the body is genuinely dynamic (`profile=PhysicsActor`); `shadow`-style collision explanations were ruled out by staging the terrain with **collision disabled entirely** and seeing the pawn still rise.
 
+**Fresh probe data (2026-11-10) — the writer is the physics sim, not an external setter.** Control (no terrain) falls and settles (300 → 78 cm); terrain rises (313 → 545 cm) with body velocity pinned to 0 and `overlaps: 0`. **Turning physics OFF at 3 s stops the rise** (`physics OFF at Z 545` → `after 1 s without physics, Z 545`), so the Chaos vehicle solver is teleporting the body (transform set directly, no velocity). Both runs have `setups=4 wheels=0`, so the missing wheels are not the trigger — control falls with 0 wheels too; the terrain is what flips fall → rise. The asset pipeline is ruled out (FBX, `SK_Vehicle_Sedan` import 476×228×144 cm, physics asset 452×205×40, `Terrain_DEM` 380×210 m all correct; the `1 cm` bounds is a stale component read). Next: bisect step 2 — a stock `AWheeledVehiclePawn` beside `AGigLineVehicle` in the terrain probe map.
+
 ### Tasks
 
 - [D] 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. **Deferred**: the chassis box, mass and gravity all measure correct, so this is not the shape of the body.