Add complete multiplayer system with real-time gameplay, challenge system, and 50x50 board option

node_modules/math-intrinsics/mod.js

@@ -0,0 +1,9 @@
+'use strict';
+
+var $floor = require('./floor');
+
+/** @type {import('./mod')} */
+module.exports = function mod(number, modulo) {
+	var remain = number % modulo;
+	return $floor(remain >= 0 ? remain : remain + modulo);
+};