Platform 0.1.6 (contact security) + fidelity fixes from the port review

- .container back in @layer components so Tailwind's px-4 still wins; unlayered it had
  quietly widened the gutter on every page
- shadow-sm -> shadow-xs: Tailwind v4 renamed the scale, so the ported markup was giving
  every white card a heavier shadow than the live site
- route changes jump to the top again instead of smooth-scrolling
- preload the wordmark font and the hero image

frontend/src/pages/Products.tsx

@@ -74,7 +74,7 @@ const ProductsPage = () => {
                 initial={{ opacity: 0 }}
                 animate={{ opacity: 1 }}
                 exit={{ opacity: 0 }}
-                className="group bg-white rounded-3xl overflow-hidden shadow-sm hover:shadow-lg hover:-translate-y-1 transition duration-300"
+                className="group bg-white rounded-3xl overflow-hidden shadow-xs hover:shadow-lg hover:-translate-y-1 transition duration-300"
               >
                 {/* Image Container */}
                 <div className="relative w-full overflow-hidden">