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/at.mjs

@@ -0,0 +1,29 @@
+//#region src/array/at.ts
+/**
+* Retrieves elements from an array at the specified indices.
+*
+* This function supports negative indices, which count from the end of the array.
+*
+* @template T
+* @param arr - The array to retrieve elements from.
+* @param indices - An array of indices specifying the positions of elements to retrieve.
+* @returns A new array containing the elements at the specified indices.
+*
+* @example
+* const numbers = [10, 20, 30, 40, 50];
+* const result = at(numbers, [1, 3, 4]);
+* console.log(result); // [20, 40, 50]
+*/
+function at(arr, indices) {
+	const result = new Array(indices.length);
+	const length = arr.length;
+	for (let i = 0; i < indices.length; i++) {
+		let index = indices[i];
+		index = Number.isInteger(index) ? index : Math.trunc(index) || 0;
+		if (index < 0) index += length;
+		result[i] = arr[index];
+	}
+	return result;
+}
+//#endregion
+export { at };