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/array/sample.d.ts

@@ -0,0 +1,18 @@
+//#region src/array/sample.d.ts
+/**
+ * Returns a random element from an array.
+ *
+ * This function takes an array and returns a single element selected randomly from the array.
+ *
+ * @template T - The type of elements in the array.
+ * @param arr - The array to sample from.
+ * @returns A random element from the array.
+ *
+ * @example
+ * const array = [1, 2, 3, 4, 5];
+ * const randomElement = sample(array);
+ * // randomElement will be one of the elements from the array, selected randomly.
+ */
+declare function sample<T>(arr: readonly T[]): T;
+//#endregion
+export { sample };