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/jiti/lib/jiti-register.mjs

@@ -0,0 +1,4 @@
+// https://nodejs.org/api/module.html#moduleregisterspecifier-parenturl-options
+import { register } from "node:module";
+
+register("./jiti-hooks.mjs", import.meta.url, {});