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/array/intersection.d.ts

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+//#region src/array/intersection.d.ts
+/**
+ * Returns the intersection of two arrays.
+ *
+ * This function takes two arrays and returns a new array containing the elements that are
+ * present in both arrays. It effectively filters out any elements from the first array that
+ * are not found in the second array.
+ *
+ * @template T - The type of elements in the array.
+ * @param firstArr - The first array to compare.
+ * @param secondArr - The second array to compare.
+ * @returns A new array containing the elements that are present in both arrays.
+ *
+ * @example
+ * const array1 = [1, 2, 3, 4, 5];
+ * const array2 = [3, 4, 5, 6, 7];
+ * const result = intersection(array1, array2);
+ * // result will be [3, 4, 5] since these elements are in both arrays.
+ */
+declare function intersection<T>(firstArr: readonly T[], secondArr: readonly T[]): T[];
+//#endregion
+export { intersection };