fix: onAuthChange memory leak in React package

Description

The onAuthChange listener in the React package is registered within useEffect hooks but never unsubscribed in the cleanup phase. This leads to a memory leak and potential duplicate executions of code within the listener when the authentication state changes.

Root Cause

In files like ChatBody.js, ChatInput.js, and EmbeddedChat.js, RCInstance.auth.onAuthChange is called inside useEffect, but the returned cleanup function does not call RCInstance.auth.removeAuthListener. Consequently, every time the effect re-runs, a new listener is added without removing the old one.

Affected Files

• packages/react/src/views/ChatBody/ChatBody.js
• packages/react/src/views/ChatInput/ChatInput.js
• packages/react/src/views/EmbeddedChat.js

Proposed Fix

Extract the callback to a named function and call removeAuthListener in the useEffect cleanup.

Start with the useEffect hooks in packages/react/src/views/ChatBody/ChatBody.js, packages/react/src/views/ChatInput/ChatInput.js, and packages/react/src/views/EmbeddedChat.js. Trace how RCInstance.auth.onAuthChange registers its callback and how the effect cleanup currently works. Done means each affected listener is removed during cleanup so rerunning the effects does not leave duplicate listeners.