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]>

scenes/maps/neon_alley/neon_alley_builder.gd

@@ -270,6 +270,7 @@ func _build_geometry() -> void:
 	_build_rail_line()
 	_build_streets()
 	_build_avenues()
+	_build_parked_cars()
 
 	if _spawn_points.is_empty():
 		_spawn_points.append(Vector3(0, 2, 0))
@@ -665,6 +666,59 @@ func _build_avenues() -> void:
 				Vector3(x, 0, z2), 0.0 if side > 0 else 180.0, lamp_scale)
 
 
+# ── Parked cars (Kenney Car Kit) ─────────────────────────────────────────────
+
+const CAR_KEYS := ["sedan", "sedan", "taxi", "van", "suv", "hatchback-sports",
+	"delivery", "sedan-sports", "police"]
+const CAR_SCALE := 1.8
+
+## A parked car: metal-tagged collider, kit body, wheels attached to the
+## model's wheel sockets, slight per-car tint.
+func _parked_car(pos: Vector3, yaw_deg: float) -> void:
+	var key: String = CAR_KEYS[_rng.randi() % CAR_KEYS.size()]
+	var body := StaticBody3D.new()
+	body.name = "Car_%d" % _rng.randi()
+	body.set_meta("acoustic_material", "metal")
+	add_child(body)
+	body.global_position = pos
+	body.rotation_degrees.y = yaw_deg + _rng.randf_range(-3.0, 3.0)
+	var shape := CollisionShape3D.new()
+	var bs := BoxShape3D.new()
+	bs.size = Vector3(2.8, 2.6, 5.0)
+	shape.shape = bs
+	shape.position = Vector3(0, 1.3, 0)
+	body.add_child(shape)
+
+	var inst: Node3D = _kit_scene_at("res://assets/props/cars/" + key + ".glb").instantiate()
+	inst.scale = Vector3.ONE * CAR_SCALE
+	inst.position.y = 0.55  # wheel contact at ground after scaling
+	body.add_child(inst)
+	var wheel_scene := _kit_scene_at("res://assets/props/cars/wheel-default.glb")
+	for n in inst.find_children("wheel*", "Node3D", true, false):
+		if n.get_child_count() == 0 and not (n is MeshInstance3D):
+			var wheel: Node3D = wheel_scene.instantiate()
+			n.add_child(wheel)
+	LevelMaterials.apply_toon_recursive(inst, 0.0)
+	# Darken under the map lighting (kit albedo clips) + per-car hue
+	_tint_recursive(inst, Color(0.62, 0.62, 0.66) * Color(1, 1, 1).lerp(Color.from_hsv(_rng.randf(), 0.6, 1.0), 0.35))
+
+
+## Seeded parking lanes hugging the curbs of the N-S streets.
+func _build_parked_cars() -> void:
+	for x in _street_lines():
+		for row in GRID:
+			_rng.seed = hash(Vector2i(int(x), row)) + 913
+			if _rng.randf() < 0.45:
+				continue
+			var z_base := (float(row) - float(GRID - 1) * 0.5) * PITCH
+			var cars := 1 + _rng.randi() % 3
+			for i in cars:
+				var side := 1.0 if _rng.randi() % 2 == 0 else -1.0
+				var cx := x + side * (ROAD_W * 0.5 - 1.8)
+				var cz := z_base + _rng.randf_range(-18.0, 18.0)
+				_parked_car(Vector3(cx, 0.02, cz), 0.0 if _rng.randi() % 2 == 0 else 180.0)
+
+
 func _kit_prop_path(path: String, pos: Vector3, yaw_deg: float, scale_f: float) -> void:
 	var inst: Node3D = _kit_scene_at(path).instantiate()
 	inst.scale = Vector3.ONE * scale_f