Pusher-js Batch Authentication Plugin

Pusher-js-auth is a client-side plugin designed to enhance the official `pusher-js` library by batching multiple private and presence channel authentication requests into a single HTTP call. This significantly improves performance and reduces network overhead when an application subscribes to numerous channels concurrently. The current stable version is 4.0.1, which is compatible exclusively with `pusher-js` versions 7.x and later. Older `pusher-js` versions (6.x and below) require the 3.x release of this plugin. While the project's release cadence is tied to major `pusher-js` updates, it provides a consistent solution for optimizing authentication workflows. Key differentiators include its seamless integration via the `authorizer` option in the `Pusher` client, and configurable `authDelay` for managing request timing. It requires a custom server-side authentication endpoint capable of processing batched channel names and returning a consolidated JSON response, which Pusher's server libraries can facilitate.