Sync local changes and new files

[vikasharma005]

This pull request includes several important fixes for the React example:

Changes Made

1. React 18 Compatibility: Updated ReactDOM.render to createRoot API
2. Node.js Polyfills: Added process.env and process.nextTick polyfills for browser environment
3. Webpack 5 Configuration: Added config-overrides.js with buffer polyfill
4. Build Process: Updated package.json to use react-app-rewired
5. Import Structure: Fixed import order and removed duplicates
6. Preflight Checks: Added .env with SKIP_PREFLIGHT_CHECK=true

Issues Fixed

• React 18 deprecation warnings
• 'process is not defined' errors
• 'process.nextTick is not a function' errors
• Page crashes when using microphone
• Import errors during build

The app now builds and runs successfully with all audio features working.