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/difference.js

@@ -0,0 +1,29 @@
+//#region src/array/difference.ts
+/**
+* Computes the difference between two arrays.
+*
+* This function takes two arrays and returns a new array containing the elements
+* that are present in the first array but not in the second array. It effectively
+* filters out any elements from the first array that also appear in the second array.
+*
+* @template T
+* @param firstArr - The array from which to derive the difference. This is the primary array
+* from which elements will be compared and filtered.
+* @param secondArr - The array containing elements to be excluded from the first array.
+* Each element in this array will be checked against the first array, and if a match is found,
+* that element will be excluded from the result.
+* @returns A new array containing the elements that are present in the first array but not
+* in the second array.
+*
+* @example
+* const array1 = [1, 2, 3, 4, 5];
+* const array2 = [2, 4];
+* const result = difference(array1, array2);
+* // result will be [1, 3, 5] since 2 and 4 are in both arrays and are excluded from the result.
+*/
+function difference(firstArr, secondArr) {
+	const secondSet = new Set(secondArr);
+	return firstArr.filter((item) => !secondSet.has(item));
+}
+//#endregion
+exports.difference = difference;