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/object/keysIn.d.mts

@@ -0,0 +1,27 @@
+//#region src/compat/object/keysIn.d.ts
+/**
+ * This function retrieves the names of string-keyed properties from an object, including those inherited from its prototype.
+ *
+ * - If the value is not an object, it is converted to an object.
+ * - Array-like objects are treated like arrays.
+ * - Sparse arrays with some missing indices are treated like dense arrays.
+ * - If the value is `null` or `undefined`, an empty array is returned.
+ * - When handling prototype objects, the `constructor` property is excluded from the results.
+ *
+ * @param [object] - The object to inspect for keys.
+ * @returns An array of string keys from the object.
+ *
+ * @example
+ * const obj = { a: 1, b: 2 };
+ * console.log(keysIn(obj)); // ['a', 'b']
+ *
+ * const arr = [1, 2, 3];
+ * console.log(keysIn(arr)); // ['0', '1', '2']
+ *
+ * function Foo() {}
+ * Foo.prototype.a = 1;
+ * console.log(keysIn(new Foo())); // ['a']
+ */
+declare function keysIn(object?: any): string[];
+//#endregion
+export { keysIn };