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/preferences/constants.js

@@ -0,0 +1,4 @@
+const SETTINGS_FILE = "settings.json";
+export {
+  SETTINGS_FILE
+};