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/cli/exec.d.ts

@@ -0,0 +1,6 @@
+import { type Options } from 'tinyexec';
+/**
+ * Improve tinyexec error logging and set `throwOnError` to `true` by default
+ * @deprecated use CommandExecutor instead
+ */
+export declare function exec(command: string, args?: string[], options?: Partial<Options>): PromiseLike<import("tinyexec").Output>;