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/fp/array/at.d.ts

@@ -0,0 +1,20 @@
+//#region src/fp/array/at.d.ts
+/**
+ * Creates a function that retrieves elements from the piped array at the specified indices.
+ *
+ * Negative indices count back from the end of the array, matching the main {@link at}
+ * implementation. Use the returned function with {@link pipe}.
+ *
+ * @template T - The type of elements in the array.
+ * @param indices - The indices of the elements to retrieve from the piped array.
+ * @returns A function that maps a readonly array to a new array of selected values.
+ *
+ * @example
+ * import { at, pipe } from 'es-toolkit/fp';
+ *
+ * pipe([10, 20, 30, 40], at([1, -1]));
+ * // => [20, 40]
+ */
+declare function at<T>(indices: number[]): (array: readonly T[]) => T[];
+//#endregion
+export { at };