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/flatMapDeep.d.ts

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+import { ExtractNestedArrayType } from "../../array/flattenDeep.js";
+
+//#region src/fp/array/flatMapDeep.d.ts
+/**
+ * Creates a function that maps each element and recursively flattens the mapped values.
+ *
+ * The iteratee receives each value and index. The returned function is lazy-capable inside
+ * {@link pipe}; a trailing short-circuiting operator can stop before later input values are mapped.
+ *
+ * @template T - The type of elements in the input array.
+ * @template U - The type returned by the iteratee before recursive flattening.
+ * @param iteratee - Called with each value and index to produce values to flatten.
+ * @returns A function that maps a readonly array to a deeply flattened array.
+ *
+ * @example
+ * import { flatMapDeep, pipe } from 'es-toolkit/fp';
+ *
+ * pipe([1, 2], flatMapDeep(value => [[value, value * 10]]));
+ * // => [1, 10, 2, 20]
+ */
+declare function flatMapDeep<T, U>(iteratee: (item: T, index: number) => U): (array: readonly T[]) => Array<ExtractNestedArrayType<U>>;
+//#endregion
+export { flatMapDeep };