[Feature] Live Mobile Presentation

[ariosavi]

Enable live presentations where the presenter controls slides, and the audience views them on their phones.

• Audience scans a QR code to join the session.
• Slides sync automatically for all viewers.
• Only the presenter can control navigation.
• Support both mobile and desktop viewers.

Blocked by

• [Feature] Add Speaker Mode #1
• [Feature] QR Code for Slides #2