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/findIndex.d.ts

@@ -0,0 +1,20 @@
+//#region src/fp/array/findIndex.d.ts
+/**
+ * Creates a function that returns the index of the first value matching a predicate.
+ *
+ * The predicate receives the value, index, and full input array. The returned function
+ * returns -1 when no value matches, matching Array.prototype.findIndex.
+ *
+ * @template T - The type of elements in the array.
+ * @param predicate - Called with each value, index, and array until it returns true.
+ * @returns A function that maps a readonly array to the first matching index, or -1.
+ *
+ * @example
+ * import { findIndex, pipe } from 'es-toolkit/fp';
+ *
+ * pipe([{ id: 1 }, { id: 2 }], findIndex(item => item.id === 2));
+ * // => 1
+ */
+declare function findIndex<T>(predicate: (value: T, index: number, array: readonly T[]) => boolean): (array: readonly T[]) => number;
+//#endregion
+export { findIndex };