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/which-pm-runs/index.js

@@ -0,0 +1,18 @@
+'use strict'
+
+module.exports = function () {
+  if (!process.env.npm_config_user_agent) {
+    return undefined
+  }
+  return pmFromUserAgent(process.env.npm_config_user_agent)
+}
+
+function pmFromUserAgent (userAgent) {
+  const pmSpec = userAgent.split(' ')[0]
+  const separatorPos = pmSpec.lastIndexOf('/')
+  const name = pmSpec.substring(0, separatorPos)
+  return {
+    name: name === 'npminstall' ? 'cnpm' : name,
+    version: pmSpec.substring(separatorPos + 1)
+  }
+}