How can I securely prevent tab switching and screen cheating during online exams using JavaScript?

I’m building an online examination system and want to improve exam security on the frontend side. Currently, I’m using JavaScript to detect tab switching, full-screen exit events, copy/paste blocking, and keyboard shortcuts during exams.

However, I want to know the best and most reliable approach for handling:

Tab switching detection

Fullscreen enforcement

Preventing copy/paste and right-click

Detecting multiple monitor usage

Browser lockdown techniques

Real-time violation tracking with WebSockets

Secure timer synchronization between client and server

What are the recommended frontend and backend coding practices for implementing these features securely without negatively affecting user experience?