Set up the HTTP server with Express, attach Socket.IO for real-time
messaging, add CORS middleware, async error handling utility, and
REST routes for room join/leave/messages/participants.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Introduce database config, MongoDB and JSON store implementations,
and a datastore factory that connects to MongoDB by default and falls
back to a local JSON file when MongoDB is unavailable.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
francesco448