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/decode-named-character-reference/index.js

@@ -0,0 +1,19 @@
+import {characterEntities} from 'character-entities'
+
+// To do: next major: use `Object.hasOwn`.
+const own = {}.hasOwnProperty
+
+/**
+ * Decode a single character reference (without the `&` or `;`).
+ * You probably only need this when you’re building parsers yourself that follow
+ * different rules compared to HTML.
+ * This is optimized to be tiny in browsers.
+ *
+ * @param {string} value
+ *   `notin` (named), `#123` (deci), `#x123` (hexa).
+ * @returns {string|false}
+ *   Decoded reference.
+ */
+export function decodeNamedCharacterReference(value) {
+  return own.call(characterEntities, value) ? characterEntities[value] : false
+}