feat(ui): move users to channel list with hover volume popup, dedicate main stage to screenshares, add ws ping

server.js

@@ -156,6 +156,10 @@ wss.on('connection', (socket, req) => {
     if (!msg || typeof msg.type !== 'string') return;
 
     switch (msg.type) {
+      case 'ping': {
+        send({ type: 'pong' });
+        break;
+      }
       case 'pos': {
         const x = Number(msg.x), y = Number(msg.y);
         if (Number.isFinite(x) && Number.isFinite(y)) {