feat(showcase): add PouchDB sample component and storage page

- Implemented PouchSample component for managing POS configurations and item inventories using PouchDB.
- Created StoragePage to encapsulate the PouchSample component.
- Added UI components page with various UI elements including buttons, forms, and data grids.
- Defined Electron type declarations for printing and auto-update functionalities.
- Extended event registry with custom application events for printing and stock updates.
- Configured Vite for the showcase application with React and Tailwind CSS support.
- Updated package.json and pnpm-lock.yaml to include necessary dependencies for the showcase app.

apps/showcase/src/main.tsx

@@ -0,0 +1,17 @@
+import './main.css';
+import { StrictMode } from 'react';
+import { createRoot } from 'react-dom/client';
+import { setupI18n } from '@repo/core-i18n';
+import App from './App';
+
+async function bootstrap() {
+  await setupI18n({}, 'en'); // Minimal i18n setup
+
+  createRoot(document.getElementById('app')!).render(
+    <StrictMode>
+      <App />
+    </StrictMode>,
+  );
+}
+
+bootstrap();