fix: multiple bug fixes

isolated users, db backup, weird disconnect issues for long voice sessions,

server/src/websocket/handler.ts

@@ -293,7 +293,13 @@ export async function handleWebSocketMessage(connectionId: string, message: WsMe
   if (!user)
     return;
 
+  user.lastPong = Date.now();
+  connectedUsers.set(connectionId, user);
+
   switch (message.type) {
+    case 'keepalive':
+      break;
+
     case 'identify':
       handleIdentify(user, message, connectionId);
       break;