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/compat/array/slice.d.ts

@@ -0,0 +1,19 @@
+//#region src/compat/array/slice.d.ts
+/**
+ * Create a slice of `array` from `start` up to, but not including, `end`.
+ *
+ * It does not return a dense array for sparse arrays unlike the native `Array.prototype.slice`.
+ *
+ * @template T - The type of the array elements.
+ * @param array - The array to slice.
+ * @param [start=0] - The start position.
+ * @param [end=array.length] - The end position.
+ * @returns Returns the slice of `array`.
+ *
+ * @example
+ * slice([1, 2, 3], 1, 2); // => [2]
+ * slice(new Array(3)); // => [undefined, undefined, undefined]
+ */
+declare function slice<T>(array: ArrayLike<T> | null | undefined, start?: number, end?: number): T[];
+//#endregion
+export { slice };