feat: parked cars across the city (Kenney Car Kit, CC0)

Streets are now populated: seeded parking lanes hug the curbs of every
N-S street with sedans, taxis, vans, SUVs, hatchbacks, delivery trucks
and the occasional police car (~100+ across the city).

- Wheels attach at the models' wheel-socket empties at spawn
- Metal-tagged box colliders: cars are cover that sounds like cover
- Toonified + darkened base tint (kit albedo clips under the map light)
  with per-car hue jitter for varied paint jobs
- Slight rotation jitter so parking reads natural, not stamped

Verified via street capture (colored cars parked down the avenue, no
clipping/glow); movement 11/11, smoke 0 failures, acoustics ALL PASSED.

Co-Authored-By: Claude Fable 5 <[email protected]>

assets/props/cars/LICENSE.txt

@@ -0,0 +1,28 @@
+	
+
+	Car Kit (3.1)
+
+	Created/distributed by Kenney (www.kenney.nl)
+	Creation date: 02-04-2026 14:03
+	
+			------------------------------
+
+	License: (Creative Commons Zero, CC0)
+	http://creativecommons.org/publicdomain/zero/1.0/
+
+	You can use this content for personal, educational, and commercial purposes.
+
+	Support by crediting 'Kenney' or 'www.kenney.nl' (this is not a requirement)
+
+			------------------------------
+
+	• Website : www.kenney.nl
+	• Donate  : www.kenney.nl/donate
+
+	• Patreon : patreon.com/kenney
+	
+	Follow on social media for updates:
+
+	• Twitter:	 twitter.com/KenneyNL
+	• BlueSky:	 kenney.bsky.social
+	• Instagram: instagram.com/kenney_nl