Bundle brainstorm server dependencies instead of requiring npm install

Vendor node_modules into the repo so the brainstorm server works
immediately on fresh plugin installs without needing npm at runtime.

skills/brainstorming/scripts/node_modules/math-intrinsics/isInteger.js

@@ -0,0 +1,16 @@
+'use strict';
+
+var $abs = require('./abs');
+var $floor = require('./floor');
+
+var $isNaN = require('./isNaN');
+var $isFinite = require('./isFinite');
+
+/** @type {import('./isInteger')} */
+module.exports = function isInteger(argument) {
+	if (typeof argument !== 'number' || $isNaN(argument) || !$isFinite(argument)) {
+		return false;
+	}
+	var absValue = $abs(argument);
+	return $floor(absValue) === absValue;
+};