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/assets/vite-plugin-assets.d.ts

@@ -0,0 +1,12 @@
+import type * as fsMod from 'node:fs';
+import type * as vite from 'vite';
+import type { Logger } from '../core/logger/core.js';
+import type { AstroSettings } from '../types/astro.js';
+interface Options {
+    settings: AstroSettings;
+    sync: boolean;
+    logger: Logger;
+    fs: typeof fsMod;
+}
+export default function assets({ fs, settings, sync, logger }: Options): vite.Plugin[];
+export {};