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/postcss/README.md

@@ -0,0 +1,29 @@
+# PostCSS
+
+<img align="right" width="95" height="95"
+     alt="Philosopher’s stone, logo of PostCSS"
+     src="https://postcss.org/logo.svg">
+
+PostCSS is a tool for transforming styles with JS plugins.
+These plugins can lint your CSS, support variables and mixins,
+transpile future CSS syntax, inline images, and more.
+
+PostCSS is used by industry leaders including Wikipedia, Twitter, Alibaba,
+and JetBrains. The [Autoprefixer] and [Stylelint] PostCSS plugins are some of the most popular CSS tools.
+
+---
+
+<img src="https://cdn.evilmartians.com/badges/logo-no-label.svg" alt="" width="22" height="16" />  Built by
+ <b><a href="https://evilmartians.com/devtools?utm_source=postcss&utm_campaign=devtools-button&utm_medium=github">Evil Martians</a></b>, go-to agency for <b>developer tools</b>.
+
+---
+
+[Abstract Syntax Tree]: https://en.wikipedia.org/wiki/Abstract_syntax_tree
+[Evil Martians]:        https://evilmartians.com/?utm_source=postcss
+[Autoprefixer]:         https://github.com/postcss/autoprefixer
+[Stylelint]:            https://stylelint.io/
+[plugins]:              https://github.com/postcss/postcss#plugins
+
+
+## Docs
+Read full docs **[here](https://postcss.org/)**.