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/diff/libesm/convert/xml.js

@@ -0,0 +1,31 @@
+/**
+ * converts a list of change objects to a serialized XML format
+ */
+export function convertChangesToXML(changes) {
+    const ret = [];
+    for (let i = 0; i < changes.length; i++) {
+        const change = changes[i];
+        if (change.added) {
+            ret.push('<ins>');
+        }
+        else if (change.removed) {
+            ret.push('<del>');
+        }
+        ret.push(escapeHTML(change.value));
+        if (change.added) {
+            ret.push('</ins>');
+        }
+        else if (change.removed) {
+            ret.push('</del>');
+        }
+    }
+    return ret.join('');
+}
+function escapeHTML(s) {
+    let n = s;
+    n = n.replace(/&/g, '&amp;');
+    n = n.replace(/</g, '&lt;');
+    n = n.replace(/>/g, '&gt;');
+    n = n.replace(/"/g, '&quot;');
+    return n;
+}