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/flattie/dist/index.js

@@ -0,0 +1,27 @@
+function iter(output, nullish, sep, val, key) {
+	var k, pfx = key ? (key + sep) : key;
+
+	if (val == null) {
+		if (nullish) output[key] = val;
+	} else if (typeof val != 'object') {
+		output[key] = val;
+	} else if (Array.isArray(val)) {
+		for (k=0; k < val.length; k++) {
+			iter(output, nullish, sep, val[k], pfx + k);
+		}
+	} else {
+		for (k in val) {
+			iter(output, nullish, sep, val[k], pfx + k);
+		}
+	}
+}
+
+function flattie(input, glue, toNull) {
+	var output = {};
+	if (typeof input == 'object') {
+		iter(output, !!toNull, glue || '.', input, '');
+	}
+	return output;
+}
+
+exports.flattie = flattie;