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/isSubset.d.ts

@@ -0,0 +1,27 @@
+//#region src/array/isSubset.d.ts
+/**
+ * Checks if the `subset` array is entirely contained within the `superset` array.
+ *
+ *
+ * @template T - The type of elements contained in the arrays.
+ * @param superset - The array that may contain all elements of the subset.
+ * @param subset - The array to check against the superset.
+ * @returns Returns `true` if all elements of the `subset` are present in the `superset`, otherwise returns `false`.
+ *
+ * @example
+ * ```typescript
+ * const superset = [1, 2, 3, 4, 5];
+ * const subset = [2, 3, 4];
+ * isSubset(superset, subset); // true
+ * ```
+ *
+ * @example
+ * ```typescript
+ * const superset = ['a', 'b', 'c'];
+ * const subset = ['a', 'd'];
+ * isSubset(superset, subset); // false
+ * ```
+ */
+declare function isSubset<T>(superset: readonly T[], subset: readonly T[]): boolean;
+//#endregion
+export { isSubset };