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/prompts/lib/dateparts/seconds.js

@@ -0,0 +1,28 @@
+'use strict';
+
+const DatePart = require('./datepart');
+
+class Seconds extends DatePart {
+  constructor(opts={}) {
+    super(opts);
+  }
+
+  up() {
+    this.date.setSeconds(this.date.getSeconds() + 1);
+  }
+
+  down() {
+    this.date.setSeconds(this.date.getSeconds() - 1);
+  }
+
+  setTo(val) {
+    this.date.setSeconds(parseInt(val.substr(-2)));
+  }
+
+  toString() {
+    let s = this.date.getSeconds();
+    return this.token.length > 1 ? String(s).padStart(2, '0') : s;
+  }
+}
+
+module.exports = Seconds;