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/rehype/index.js

@@ -0,0 +1,10 @@
+// Note: types exposed from `index.d.ts`
+import rehypeParse from 'rehype-parse'
+import rehypeStringify from 'rehype-stringify'
+import {unified} from 'unified'
+
+/**
+ * Create a new unified processor that already uses `rehype-parse` and
+ * `rehype-stringify`.
+ */
+export const rehype = unified().use(rehypeParse).use(rehypeStringify).freeze()