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/infra/process-operating-system-provider.js

@@ -0,0 +1,12 @@
+class ProcessOperatingSystemProvider {
+  #platformToOs = {
+    darwin: "macOS",
+    win32: "Windows",
+    linux: "Linux"
+  };
+  name = process.platform;
+  displayName = `${this.#platformToOs[this.name] ?? this.name} (${process.arch})`;
+}
+export {
+  ProcessOperatingSystemProvider
+};