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/union.js

@@ -0,0 +1,24 @@
+const require_uniq = require("./uniq.js");
+//#region src/array/union.ts
+/**
+* Creates an array of unique values from all given arrays.
+*
+* This function takes two arrays, merges them into a single array, and returns a new array
+* containing only the unique values from the merged array.
+*
+* @template T - The type of elements in the array.
+* @param arr1 - The first array to merge and filter for unique values.
+* @param arr2 - The second array to merge and filter for unique values.
+* @returns A new array of unique values.
+*
+* @example
+* const array1 = [1, 2, 3];
+* const array2 = [3, 4, 5];
+* const result = union(array1, array2);
+* // result will be [1, 2, 3, 4, 5]
+*/
+function union(arr1, arr2) {
+	return require_uniq.uniq(arr1.concat(arr2));
+}
+//#endregion
+exports.union = union;