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/server/render/dom.d.ts

@@ -0,0 +1,3 @@
+import type { SSRResult } from '../../../types/public/internal.js';
+export declare function componentIsHTMLElement(Component: unknown): boolean;
+export declare function renderHTMLElement(result: SSRResult, constructor: typeof HTMLElement, props: any, slots: any): Promise<string>;