test(visual): the vehicle shot gets a reference, and the character/car height fixes

The suite caught an incomplete target: demo-vehicle had an empty references list, which the
visual-loop test requires. It now points at Art/blender/vehicle/hatch-reference.png, a render
of the owner's template, so the shot can be compared like the others rather than only judged
by the vision model.

Tools/visual_targets.json

@@ -104,8 +104,10 @@
         1920,
         1080
       ],
-      "references": [],
+      "references": [
-      "expect": "A red sedan parked on the road seen from the front three-quarter: body, cabin, four wheels visible, sitting on the surface rather than floating or sunk"
+        "Art/blender/vehicle/hatch-reference.png"
+      ],
+      "expect": "The hot hatch from Art/blender/vehicle/hot hatch.blend: dark body, glazing, four wheels, resting on the road surface"
     }
   ]
 }