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/common-ancestor-path/index.js

@@ -0,0 +1,17 @@
+const {parse, sep, normalize: norm} = require('path')
+
+function* commonArrayMembers (a, b) {
+  const [l, s] = a.length > b.length ? [a, b] : [b, a]
+  for (const x of s) {
+    if (x === l.shift())
+      yield x
+    else
+      break
+  }
+}
+
+const commonAncestorPath = (a, b) => a === b ? a
+  : parse(a).root !== parse(b).root ? null
+  : [...commonArrayMembers(norm(a).split(sep), norm(b).split(sep))].join(sep)
+
+module.exports = (...paths) => paths.reduce(commonAncestorPath)