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/xorBy.d.mts

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+//#region src/array/xorBy.d.ts
+/**
+ * Computes the symmetric difference between two arrays using a custom mapping function.
+ * The symmetric difference is the set of elements which are in either of the arrays,
+ * but not in their intersection, determined by the result of the mapping function.
+ *
+ * @template T - Type of elements in the input arrays.
+ * @template U - Type of the values returned by the mapping function.
+ *
+ * @param arr1 - The first array.
+ * @param arr2 - The second array.
+ * @param mapper - The function to map array elements to comparison values.
+ * @returns An array containing the elements that are present in either `arr1` or `arr2` but not in both, based on the values returned by the mapping function.
+ *
+ * @example
+ * // Custom mapping function for objects with an 'id' property
+ * const idMapper = obj => obj.id;
+ * xorBy([{ id: 1 }, { id: 2 }], [{ id: 2 }, { id: 3 }], idMapper);
+ * // Returns [{ id: 1 }, { id: 3 }]
+ */
+declare function xorBy<T, U>(arr1: readonly T[], arr2: readonly T[], mapper: (item: T) => U): T[];
+//#endregion
+export { xorBy };