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/remark-gfm/index.d.ts

@@ -0,0 +1,13 @@
+import type {Options as MicromarkOptions} from 'micromark-extension-gfm'
+import type {Options as MdastOptions} from 'mdast-util-gfm'
+
+export {default} from './lib/index.js'
+
+/**
+ * Configuration for `remark-gfm`.
+ *
+ * Currently supports `singleTilde` as a parse option and
+ * `firstLineBlank`, `stringLength`, `tableCellPadding`, and `tablePipeAlign`
+ * as serialization options.
+ */
+export interface Options extends MicromarkOptions, MdastOptions {}