Add settings page for managing forecasting API key and URL via UI

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/node_modules/es-abstract/2022/Number/toString.js

@@ -0,0 +1,16 @@
+'use strict';
+
+var GetIntrinsic = require('get-intrinsic');
+
+var $String = GetIntrinsic('%String%');
+var $TypeError = require('es-errors/type');
+
+// https://262.ecma-international.org/11.0/#sec-numeric-types-number-tostring
+
+module.exports = function NumberToString(x) {
+	if (typeof x !== 'number') {
+		throw new $TypeError('Assertion failed: `x` must be a Number');
+	}
+
+	return $String(x);
+};