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.

MEMORY.md

@@ -680,3 +680,31 @@ A visual change needs **build → import → render**, never just a render: `ren
 - The hero facade rework (split out of 0.3.0) is **closed at "surface detail that reads at 45 m"**. Done and committed: carved inscription, stepped medallions, light motto band + proud surround (all three had been buried inside the parapet), and gold JIMMY KIMMEL LIVE banner lettering.
 - **Banner lettering is procedural, not ComfyUI.** `Tools/gen/generate_banner_texture.py` draws the exact title with Pillow + Liberation Sans Bold. An image model (Qwen-Image 2.1) would mangle a trademark string and is research-only, so for a _known_ string a font rasteriser is strictly better than txt2img. Reserve ComfyUI/Qwen for things that need a model, not for literal text.
 - **Deferred to 0.9.0 (owner's instruction):** volute capital depth, lattice grille depth, and the full realism pass (banded rustication, measured materials, texel density, LOD/collision). The 0.9.0 "Hero façade (6840)" item records the hand-off.
+
+## 2026-11-10 — Vehicle launch: the asset pipeline is ruled out
+
+Re-checked the three "asset is broken" suspects with commandlets and each is **correct**:
+
+- `vehicle_skeletal.fbx` geometry is X −2.38..2.38 m (the full car, 296 verts), not degenerate.
+- Imported `SK_Vehicle_Sedan` bounds are **origin (0,0,72) extent (238,114,72) cm** — the correct 4.76 x 2.28 x 1.44 m car, so the import scale is fine.
+- `Terrain_DEM` bounds are 380 x 210 m with no degenerate/NaN scale, and its body setup reports no convex/box/sphere elements.
+
+So the "1 cm bounds" logged in the vehicle diagnostic is a **stale runtime read of the component bounds**, not an asset defect — the skeletal mesh is fine and the symptom is the teleport writing the actor transform, not a bad mesh. The launch is a runtime (Chaos movement / map) problem, not an import or build one.
+
+## 2026-11-10 — Vehicle launch: fresh probe data, the writer is the physics sim
+
+Rebuilt and re-ran the `ue_vehicle_probe_map.py` workflow (after `chmod u+w` the read-only `.umap`s and `rm` the four stale `VehicleProbe*` maps — `delete_asset` leaves the `.umap` on disk so the tool's own fallback never fires):
+
+| t    | control (no terrain)      | terrain                         |
+| ---- | ------------------------- | ------------------------------- |
+| 0.03 | Z 300 vZ 0                | Z 313 vZ 0                      |
+| 1.50 | Z 306 vZ 0                | Z 442 vZ 0                      |
+| 2.25 | Z 299 **vZ −242** (falls) | Z 545 **vZ 1** (jumps up)       |
+| 3.0  | settles Z 78              | settles Z 545, then physics OFF |
+
+- **Control falls and settles** (300 → 78 cm); **terrain rises** (313 → 545 cm) with the body velocity pinned to 0 throughout 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 writer is the physics simulation (Chaos vehicle solver teleporting the body, transform set directly), **not** an external `SetActorLocation` — the "transform written directly" reads that way because the solver moves the body without a velocity.
+- **0 wheels in both runs** (control also has `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 `1 cm` bounds (`extent 1,1,1`) persist in the diagnostic and are a **stale component read**, not the mesh (the imported `SK_Vehicle_Sedan` bounds are the correct 476 × 228 × 144 cm).
+
+Next: the bisect plan step 2 — spawn a **stock `AWheeledVehiclePawn`** with `SK_Vehicle_Sedan` beside `AGigLineVehicle` in the terrain probe map. If the stock pawn also rises, the asset + terrain interaction is at fault; if it settles, `AGigLineVehicle`'s setup (movement subclass, mass override, panel attachment) is.