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/env/errors.d.ts

@@ -0,0 +1,7 @@
+import type { ValidationResultErrors } from './validators.js';
+export interface InvalidVariable {
+    key: string;
+    type: string;
+    errors: ValidationResultErrors;
+}
+export declare function invalidVariablesToError(invalid: Array<InvalidVariable>): string[];