refactor: Move Astro to root, use PORT env (default 80), allow all hosts

- Move Astro files from dealplustech-astro/ to project root
- Update Dockerfile: PORT environment variable (default 80)
- Add vite.config.ts with allowedHosts: true
- Matches nixpacks behavior for Easypanel deployment
- No hardcoded ports or domains

node_modules/@astrojs/markdown-remark/dist/import-plugin-browser.js

@@ -0,0 +1,7 @@
+async function importPlugin(p) {
+  const importResult = await import(p);
+  return importResult.default;
+}
+export {
+  importPlugin
+};