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/mdast-util-gfm/index.d.ts

@@ -0,0 +1,12 @@
+import type {ToMarkdownOptions as FootnoteOptions} from 'mdast-util-gfm-footnote'
+import type {Options as TableOptions} from 'mdast-util-gfm-table'
+
+/**
+ * Configuration for `gfmToMarkdown` from `mdast-util-gfm`.
+ *
+ * Currently supports options for `mdast-util-gfm-footnote` and
+ * `mdast-util-gfm-table`.
+ */
+export interface Options extends FootnoteOptions, TableOptions {}
+
+export {gfmFromMarkdown, gfmToMarkdown} from './lib/index.js'