feat: update client package dependencies and Rollup configuration

- Added rollup-plugin-postcss to package.json and updated package-lock.json.
- Enhanced Rollup configuration to include postcss plugin for CSS handling.
- Updated index.ts to export all components from the components directory for better modularity.

packages/client/src/index.ts

@@ -1,9 +1,10 @@
 // Components
-export { default as Toast } from './components/Toast';
+export * from './components';
 
 // Hooks
 export * from './hooks';
 
+export * from './common';
 // Common types
 export * from './common/types';