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/content/index.d.ts

@@ -0,0 +1,6 @@
+export { attachContentServerListeners } from './server-listeners.js';
+export { createContentTypesGenerator } from './types-generator.js';
+export { getContentPaths, hasAssetPropagationFlag } from './utils.js';
+export { astroContentAssetPropagationPlugin } from './vite-plugin-content-assets.js';
+export { astroContentImportPlugin } from './vite-plugin-content-imports.js';
+export { astroContentVirtualModPlugin } from './vite-plugin-content-virtual-mod.js';