test(vehicle): a review shot, and the judge that proves the car is missing

Adds demo-vehicle to the camera list and the visual targets, plus shot 9 in
Screenshots/README.md - marked FAIL, because that is what it shows.

The vehicle is staged and runs: spawned at (-12950,-900,120), 9 visual panels attached,
panel 0 visible with a 238 cm extent, settled at Z 119 cm. The capture shows an empty road
with a soft shadow. Two checks disagree in a useful way: visual_loop --verify PASSES the
frame (it only tests size, blankness and tonal range, so a well-exposed empty road passes),
while judge_screenshot returns verdict=no confidence=1.0.

Strongest clue, recorded in TODO.md: a downward trace from the vehicle finds no ground at
all (ground at Z -9999), so the car sits over a surface without collision or inside
geometry - the shadow and the panels are not in the same place.

Diagnostics added along the way: mesh/visibility/bounds at BeginPlay, per-panel world
positions and extents, and the ground trace. The visual panels were also unhidden from the
physics mesh: SetVisibility(false, ...) hid them whether or not propagation was requested.

Screenshots/README.md

@@ -26,6 +26,7 @@ Every shot is embedded below, in order, so the whole review happens in this file
 | 6 | [Third-person body](#6-third-person-body) | ☑ 2026-11-09 | ☑ 2026-11-09 |
 | 7 | [Third-person front](#7-third-person-front) | ☑ 2026-11-09 | ☑ 2026-11-09 |
 | 8 | [Third-person walk](#8-third-person-walk) | ☑ 2026-11-09 | ☑ 2026-11-09 |
+| 9 | [Vehicle](#9-vehicle) | ☐ FAIL 2026-11-09 | ☐ pending |
 
 **Verified** is what `--verify` reports: the frame is not blank, is the right size, and has tonal range. **Approved** is the owner's verdict, recorded here. Each shot also has an **expectation** in [`Tools/visual_targets.json`](../Tools/visual_targets.json) describing the content it must show.