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/csso/lib/replace/Url.js

@@ -0,0 +1,4 @@
+export default function(node) {
+    // convert `\\` to `/`
+    node.value = node.value.replace(/\\/g, '/');
+};