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/difference.d.mts

@@ -0,0 +1,21 @@
+//#region src/fp/array/difference.d.ts
+/**
+ * Creates a function that returns values from the piped array that are not present in another array.
+ *
+ * Equality follows SameValueZero through Set membership, matching the main
+ * {@link difference} implementation. The returned function is lazy-capable
+ * inside {@link pipe}.
+ *
+ * @template T - The type of elements in the arrays.
+ * @param secondArray - Values to exclude from the piped array.
+ * @returns A function that maps the piped array to its difference.
+ *
+ * @example
+ * import { difference, pipe } from 'es-toolkit/fp';
+ *
+ * pipe([1, 2, 3], difference([2, 4]));
+ * // => [1, 3]
+ */
+declare function difference<T>(secondArray: readonly T[]): (array: readonly T[]) => T[];
+//#endregion
+export { difference };