fix: Fix product page syntax errors

1. Remove duplicate/broken code in product tables section
2. Fix PostCSS config for Tailwind 4
3. Add @tailwindcss/postcss dependency
4. Remove --production flag from Dockerfile (sharp required)

All fixes enable successful Docker build with favicon working.

node_modules/astro/dist/runtime/client/visible.d.ts

@@ -0,0 +1,8 @@
+import type { ClientDirective } from '../../types/public/integrations.js';
+/**
+ * Hydrate this component when one of it's children becomes visible
+ * We target the children because `astro-island` is set to `display: contents`
+ * which doesn't work with IntersectionObserver
+ */
+declare const visibleDirective: ClientDirective;
+export default visibleDirective;