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/regex/dist/esm/backcompat.d.ts

@@ -0,0 +1,8 @@
+/**
+Applies flag v rules when using flag u, for forward compatibility.
+Assumes flag u and doesn't worry about syntax errors that are caught by it.
+@param {string} expression
+@returns {PluginResult}
+*/
+export function backcompatPlugin(expression: string): PluginResult;
+import type { PluginResult } from './regex.js';