feat: Production-ready configurator with Dutch standards, pricing & visual UI

- Update door-models.ts: 7mm VSG 33.1 safety glass, 15mm offset, Taats pivot 60mm
- Add pricing engine (lib/pricing.ts): steel €45/m + glass €140/m² + €650 base
- Wire reactive pricing into Zustand store on every config change
- Fix 3D materials: glass thickness 0.007m, corrected roughness/metalness
- Upgrade scene: apartment environment, wider contact shadows
- Add Dutch height presets: Renovatie 2015mm, Nieuwbouw 2315mm, Plafondhoog 2500mm
- Replace text buttons with visual SVG tiles for door type & grid selection

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

components/configurator/scene.tsx

@@ -230,16 +230,16 @@ export function Scene3D() {
       {/* Premium Studio Lighting */}
       <Lighting />
 
-      {/* Studio Environment for photorealistic steel reflections */}
-      <Environment preset="studio" environmentIntensity={1.0} />
+      {/* Apartment Environment for warm, realistic steel reflections */}
+      <Environment preset="apartment" blur={0.6} environmentIntensity={1.2} />
 
       {/* High-Resolution Contact Shadows for grounding */}
       <ContactShadows
         position={[0, 0.01, 0]}
         opacity={0.6}
-        scale={15}
-        blur={2}
-        far={2}
+        scale={20}
+        blur={2.5}
+        far={4}
         resolution={2048}
       />