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/differenceBy.js

@@ -0,0 +1,41 @@
+//#region src/array/differenceBy.ts
+/**
+* Computes the difference between two arrays after mapping their elements through a provided function.
+*
+* This function takes two arrays and a mapper function. It returns a new array containing the elements
+* that are present in the first array but not in the second array, based on the identity calculated
+* by the mapper function.
+*
+* Essentially, it filters out any elements from the first array that, when
+* mapped, match an element in the mapped version of the second array.
+*
+* @template T, U
+* @param firstArr - The primary array from which to derive the difference.
+* @param secondArr - The array containing elements to be excluded from the first array.
+* @param mapper - The function to map the elements of both arrays. This function
+* is applied to each element in both arrays, and the comparison is made based on the mapped values.
+* @returns A new array containing the elements from the first array that do not have a corresponding
+* mapped identity in the second array.
+*
+* @example
+* const array1 = [{ id: 1 }, { id: 2 }, { id: 3 }];
+* const array2 = [{ id: 2 }, { id: 4 }];
+* const mapper = item => item.id;
+* const result = differenceBy(array1, array2, mapper);
+* // result will be [{ id: 1 }, { id: 3 }] since the elements with id 2 are in both arrays and are excluded from the result.
+*
+* @example
+* const array1 = [{ id: 1 }, { id: 2 }, { id: 3 }];
+* const array2 = [2, 4];
+* const mapper = item => (typeof item === 'object' ? item.id : item);
+* const result = differenceBy(array1, array2, mapper);
+* // result will be [{ id: 1 }, { id: 3 }] since 2 is present in both arrays after mapping, and is excluded from the result.
+*/
+function differenceBy(firstArr, secondArr, mapper) {
+	const mappedSecondSet = new Set(secondArr.map((item) => mapper(item)));
+	return firstArr.filter((item) => {
+		return !mappedSecondSet.has(mapper(item));
+	});
+}
+//#endregion
+exports.differenceBy = differenceBy;