feat: voucher purchase flow

webpack.config.js

@@ -25,6 +25,8 @@ Encore
     .copyFiles([
         {from: './assets/images', to: 'images/[path][name].[hash:8].[ext]'},
         {from: './assets/favicon', to: 'favicon/[path][name].[hash:8].[ext]'},
+        // voucher thumbnails only; the PDFs beside them are source material and not shipped
+        {from: './assets/vouchers', to: 'images/vouchers/[path][name].[hash:8].[ext]', pattern: /\.jpg$/},
     ])
 ;