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/mdast-util-to-markdown/lib/util/association.js

@@ -0,0 +1,33 @@
+/**
+ * @import {AssociationId} from '../types.js'
+ */
+
+import {decodeString} from 'micromark-util-decode-string'
+
+/**
+ * Get an identifier from an association to match it to others.
+ *
+ * Associations are nodes that match to something else through an ID:
+ * <https://github.com/syntax-tree/mdast#association>.
+ *
+ * The `label` of an association is the string value: character escapes and
+ * references work, and casing is intact.
+ * The `identifier` is used to match one association to another:
+ * controversially, character escapes and references don’t work in this
+ * matching: `&copy;` does not match `©`, and `\+` does not match `+`.
+ *
+ * But casing is ignored (and whitespace) is trimmed and collapsed: ` A\nb`
+ * matches `a b`.
+ * So, we do prefer the label when figuring out how we’re going to serialize:
+ * it has whitespace, casing, and we can ignore most useless character
+ * escapes and all character references.
+ *
+ * @type {AssociationId}
+ */
+export function association(node) {
+  if (node.label || !node.identifier) {
+    return node.label || ''
+  }
+
+  return decodeString(node.identifier)
+}