Koa Shopify Authentication Middleware

simple-koa-shopify-auth is a Koa middleware library designed to simplify Shopify app authentication, serving as a successor to the now-deprecated `@shopify/koa-shopify-auth`. It specifically supports `@shopify/shopify-api` version 5.x.x, integrating features like token exchange for online sessions and removing cookie-based session management to reduce redirects. The package is currently at version 3.0.0, with patch updates for performance and bug fixes, but the project is officially considered deprecated by its maintainer due to ongoing improvements in Shopify's native authentication flows that will render such a library unnecessary. It differentiates itself by its explicit support for `@shopify/shopify-api` v5 and its streamlined session handling, but it is not affiliated with Shopify directly. There are no plans to support `@shopify/shopify-api` v6 or newer versions, making it suitable only for applications locked into the v5 API.