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/vite-plugin-astro-server/metadata.d.ts

@@ -0,0 +1,3 @@
+import type { ModuleLoader } from '../core/module-loader/index.js';
+import type { SSRResult } from '../types/public/internal.js';
+export declare function getComponentMetadata(filePath: URL, loader: ModuleLoader): Promise<SSRResult['componentMetadata']>;