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/tailwindcss/dist/lib.d.ts

@@ -0,0 +1,3 @@
+declare function postcssPluginWarning(): void;
+
+export { postcssPluginWarning as default };