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/error.d.ts

@@ -0,0 +1,7 @@
+import type { ModuleLoader } from '../core/module-loader/index.js';
+import type { AstroConfig } from '../types/public/config.js';
+import type { DevPipeline } from './pipeline.js';
+export declare function recordServerError(loader: ModuleLoader, config: AstroConfig, { logger }: DevPipeline, _err: unknown): {
+    error: Error;
+    errorWithMetadata: import("../core/errors/errors.js").ErrorWithMetadata;
+};