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/castArray.mjs

@@ -0,0 +1,33 @@
+//#region src/compat/array/castArray.ts
+/**
+* Casts value as an array if it's not one.
+*
+* @template T The type of elements in the array.
+* @param value The value to be cast to an array.
+* @returns An array containing the input value if it wasn't an array, or the original array if it was.
+*
+* @example
+* const arr1 = castArray(1);
+* // Returns: [1]
+*
+* const arr2 = castArray([1]);
+* // Returns: [1]
+*
+* const arr3 = castArray({'a': 1});
+* // Returns: [{'a': 1}]
+*
+* const arr4 = castArray(null);
+* // Returns: [null]
+*
+* const arr5 = castArray(undefined);
+* // Returns: [undefined]
+*
+* const arr6 = castArray();
+* // Returns: []
+*/
+function castArray(value) {
+	if (arguments.length === 0) return [];
+	return Array.isArray(value) ? value : [value];
+}
+//#endregion
+export { castArray };