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/css-tree/lib/syntax/atrule/nest.js

@@ -0,0 +1,12 @@
+export default {
+    parse: {
+        prelude() {
+            return this.createSingleNodeList(
+                this.SelectorList()
+            );
+        },
+        block() {
+            return this.Block(true);
+        }
+    }
+};