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/dset/merge/index.d.ts

@@ -0,0 +1,2 @@
+export function merge(foo: any, bar: any): any; // TODO
+export function dset<T extends object, V>(obj: T, keys: string | ArrayLike<string | number>, value: V): void;