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/string/toUpper.d.mts

@@ -0,0 +1,21 @@
+//#region src/compat/string/toUpper.d.ts
+/**
+ * Converts `string`, as a whole, to upper case just like
+ * [String#toUpperCase](https://mdn.io/toUpperCase).
+ *
+ * @param [value=''] The value to convert.
+ * @returns Returns the upper cased string.
+ * @example
+ *
+ * toUpper('--foo-bar--');
+ * // => '--FOO-BAR--'
+ *
+ * toUpper(null);
+ * // => ''
+ *
+ * toUpper([1, 2, 3]);
+ * // => '1,2,3'
+ */
+declare function toUpper<T extends string = string>(value?: T): Uppercase<T>;
+//#endregion
+export { toUpper };