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/metadata.d.ts

@@ -0,0 +1,4 @@
+import type { ModuleInfo } from '../core/module-loader/index.js';
+import type { PluginMetadata } from './types.js';
+export declare function getAstroMetadata(modInfo: ModuleInfo): PluginMetadata['astro'] | undefined;
+export declare function createDefaultAstroMetadata(): PluginMetadata['astro'];