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/@astrojs/markdown-remark/dist/remark-collect-images.d.ts

@@ -0,0 +1,4 @@
+import type { Root } from 'mdast';
+import type { VFile } from 'vfile';
+import type { AstroMarkdownProcessorOptions } from './types.js';
+export declare function remarkCollectImages(opts: AstroMarkdownProcessorOptions['image']): (tree: Root, vfile: VFile) => void;