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/hast-util-is-element/index.d.ts

@@ -0,0 +1,4 @@
+export type Check = import('./lib/index.js').Check;
+export type Test = import('./lib/index.js').Test;
+export type TestFunction = import('./lib/index.js').TestFunction;
+export { convertElement, isElement } from "./lib/index.js";