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/astro/dist/actions/runtime/utils.js

@@ -0,0 +1,16 @@
+const ACTION_API_CONTEXT_SYMBOL = Symbol.for("astro.actionAPIContext");
+const formContentTypes = ["application/x-www-form-urlencoded", "multipart/form-data"];
+function hasContentType(contentType, expected) {
+  const type = contentType.split(";")[0].toLowerCase();
+  return expected.some((t) => type === t);
+}
+function isActionAPIContext(ctx) {
+  const symbol = Reflect.get(ctx, ACTION_API_CONTEXT_SYMBOL);
+  return symbol === true;
+}
+export {
+  ACTION_API_CONTEXT_SYMBOL,
+  formContentTypes,
+  hasContentType,
+  isActionAPIContext
+};