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/web-namespaces/index.js

@@ -0,0 +1,13 @@
+/**
+ * Map of web namespaces.
+ *
+ * @type {Record<string, string>}
+ */
+export const webNamespaces = {
+  html: 'http://www.w3.org/1999/xhtml',
+  mathml: 'http://www.w3.org/1998/Math/MathML',
+  svg: 'http://www.w3.org/2000/svg',
+  xlink: 'http://www.w3.org/1999/xlink',
+  xml: 'http://www.w3.org/XML/1998/namespace',
+  xmlns: 'http://www.w3.org/2000/xmlns/'
+}