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-to-html/lib/handle/root.js

@@ -0,0 +1,22 @@
+/**
+ * @import {Parents, Root} from 'hast'
+ * @import {State} from '../index.js'
+ */
+
+/**
+ * Serialize a root.
+ *
+ * @param {Root} node
+ *   Node to handle.
+ * @param {number | undefined} _1
+ *   Index of `node` in `parent.
+ * @param {Parents | undefined} _2
+ *   Parent of `node`.
+ * @param {State} state
+ *   Info passed around about the current state.
+ * @returns {string}
+ *   Serialized node.
+ */
+export function root(node, _1, _2, state) {
+  return state.all(node)
+}