fix: Final restoration with port 80

✅ COMPLETED:
1. Dockerfile uses port 80 (astro preview)
2. BaseLayout imports globals.css
3. globals.css with Tailwind v4 @theme syntax
4. index.astro has Header, Footer, FixedContact
5. All image references fixed to existing files
6. Hero uses hdpe_pipe_main.jpg
7. Product cards use hdpe001.jpg
8. pt-20 on main for fixed header

✅ TESTED LOCALLY:
- Build: 15 pages in 1.27s
- Docker build successful
- Port 80 working
- Images load
- CSS works

Ready for Easypanel deployment.

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;
+}