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-toolkit/dist/compat/predicate/isNaN.mjs

@@ -0,0 +1,19 @@
+import { isNumber } from "./isNumber.mjs";
+//#region src/compat/predicate/isNaN.ts
+/**
+* Checks if the value is NaN.
+*
+* @param value - The value to check.
+* @returns `true` if the value is NaN, `false` otherwise.
+*
+* @example
+* isNaN(NaN); // true
+* isNaN(0); // false
+* isNaN('NaN'); // false
+* isNaN(undefined); // false
+*/
+function isNaN(value) {
+	return isNumber(value) && Number.isNaN(Number(value));
+}
+//#endregion
+export { isNaN };