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/toFilled.d.ts

@@ -0,0 +1,23 @@
+//#region src/fp/array/toFilled.d.ts
+/**
+ * Creates a function that returns a filled copy of an array.
+ *
+ * The returned function follows Array.prototype.fill indexing semantics through the main
+ * {@link toFilled} implementation and does not mutate the input array.
+ *
+ * @template T - The type of elements in the input array.
+ * @template U - The type of the fill value.
+ * @param value - The value to write into the returned array.
+ * @param start - The start index. Defaults to 0.
+ * @param end - The end index. Defaults to the array length.
+ * @returns A function that maps a readonly array to a filled copy.
+ *
+ * @example
+ * import { pipe, toFilled } from 'es-toolkit/fp';
+ *
+ * pipe([1, 2, 3], toFilled(0, 1));
+ * // => [1, 0, 0]
+ */
+declare function toFilled<T, U>(value: U, start?: number, end?: number): (array: readonly T[]) => Array<T | U>;
+//#endregion
+export { toFilled };