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/isEmptyObject.mjs

@@ -0,0 +1,19 @@
+import { isPlainObject } from "./isPlainObject.mjs";
+//#region src/predicate/isEmptyObject.ts
+/**
+* Checks if a value is an empty plain object.
+*
+* @param value - The value to check.
+* @returns True if the value is an empty plain object, otherwise false.
+*
+* @example
+* isEmptyObject({}); // true
+* isEmptyObject({ a: 1 }); // false
+* isEmptyObject([]); // false
+* isEmptyObject(null); // false
+*/
+function isEmptyObject(value) {
+	return isPlainObject(value) && Object.keys(value).length === 0;
+}
+//#endregion
+export { isEmptyObject };