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/predicate/isBrowser.js

@@ -0,0 +1,20 @@
+//#region src/predicate/isBrowser.ts
+/**
+* Checks if the current environment is a browser.
+*
+* This function checks for the existence of the `window.document` property,
+* which only exists in browser environments.
+*
+* @returns `true` if the current environment is a browser, otherwise `false`.
+*
+* @example
+* if (isBrowser()) {
+*   console.log("This is running in a browser");
+*   document.getElementById('app').innerHTML = 'Hello World';
+* }
+*/
+function isBrowser() {
+	return typeof window !== "undefined" && window?.document != null;
+}
+//#endregion
+exports.isBrowser = isBrowser;