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/object/flattenObject.d.mts

@@ -0,0 +1,39 @@
+//#region src/object/flattenObject.d.ts
+interface FlattenObjectOptions {
+  /**
+   * The delimiter to use between nested keys.
+   * @default '.'
+   */
+  delimiter?: string;
+}
+/**
+ * Flattens a nested object into a single level object with delimiter-separated keys.
+ *
+ * @param object - The object to flatten.
+ * @param [options.delimiter='.'] - The delimiter to use between nested keys.
+ * @returns The flattened object.
+ *
+ * @example
+ * const nestedObject = {
+ *   a: {
+ *     b: {
+ *       c: 1
+ *     }
+ *   },
+ *   d: [2, 3]
+ * };
+ *
+ * const flattened = flattenObject(nestedObject);
+ * console.log(flattened);
+ * // Output:
+ * // {
+ * //   'a.b.c': 1,
+ * //   'd.0': 2,
+ * //   'd.1': 3
+ * // }
+ */
+declare function flattenObject(object: object, {
+  delimiter
+}?: FlattenObjectOptions): Record<string, any>;
+//#endregion
+export { flattenObject };