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/mdast-util-to-hast/lib/handlers/table-cell.js

@@ -0,0 +1,29 @@
+/**
+ * @import {Element} from 'hast'
+ * @import {TableCell} from 'mdast'
+ * @import {State} from '../state.js'
+ */
+
+/**
+ * Turn an mdast `tableCell` node into hast.
+ *
+ * @param {State} state
+ *   Info passed around.
+ * @param {TableCell} node
+ *   mdast node.
+ * @returns {Element}
+ *   hast node.
+ */
+export function tableCell(state, node) {
+  // Note: this function is normally not called: see `table-row` for how rows
+  // and their cells are compiled.
+  /** @type {Element} */
+  const result = {
+    type: 'element',
+    tagName: 'td', // Assume body cell.
+    properties: {},
+    children: state.all(node)
+  }
+  state.patch(node, result)
+  return state.applyData(node, result)
+}