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/astro/dist/runtime/client/visible.prebuilt.js

@@ -0,0 +1,4 @@
+var visible_prebuilt_default = `(()=>{var a=(s,i,o)=>{let r=async()=>{await(await s())()},t=typeof i.value=="object"?i.value:void 0,c={rootMargin:t==null?void 0:t.rootMargin},n=new IntersectionObserver(e=>{for(let l of e)if(l.isIntersecting){n.disconnect(),r();break}},c);for(let e of o.children)n.observe(e)};(self.Astro||(self.Astro={})).visible=a;window.dispatchEvent(new Event("astro:visible"));})();`;
+export {
+  visible_prebuilt_default as default
+};