feat(tools): declarative site terrain baker and calibration recipe

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

tools/sites/vehicle_test_terrain_recipe.gd

@@ -0,0 +1,25 @@
+class_name VehicleTestTerrainRecipe
+extends RefCounted
+
+const SiteTerrainBaker = preload("res://tools/site_terrain_baker.gd")
+
+
+static func recipe() -> SiteTerrainBaker.Recipe:
+	var result := SiteTerrainBaker.Recipe.new()
+	result.columns = 61
+	result.rows = 69
+	result.cell_size_m = 3.0
+	result.origin_x_m = -90.0
+	result.origin_z_m = -176.0
+	result.floor_elevation_m = -95.0
+	result.rock_slope_degrees = 20.0
+	result.primitives = [
+		SiteTerrainBaker.SlopedPlane.new(40.0, 0.0, 0.19, 0.0, 28.0),
+		SiteTerrainBaker.Blob.new(Vector2(-24.0, -48.0), sqrt(210.0), sqrt(980.0), 13.0),
+		SiteTerrainBaker.Blob.new(Vector2(25.0, -58.0), sqrt(250.0), sqrt(1150.0), 15.0),
+		SiteTerrainBaker.Blob.new(Vector2(0.0, -66.0), sqrt(120.0), sqrt(2500.0), -8.5),
+		SiteTerrainBaker.Blob.new(Vector2(-5.0, -125.0), sqrt(900.0), sqrt(620.0), 8.0),
+		SiteTerrainBaker.Ripples.new(Vector2(1.0, 0.0), TAU / 0.075, 0.9, Vector2.ZERO, 0.0),
+		SiteTerrainBaker.Ripples.new(Vector2(0.0, 1.0), TAU / 0.048, 0.9, Vector2.ZERO, 0.0),
+	]
+	return result