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/lowerFirst.d.mts

@@ -0,0 +1,15 @@
+//#region src/compat/string/lowerFirst.d.ts
+/**
+ * Converts the first character of string to lower case.
+ *
+ * @param str - The string that is to be changed
+ * @returns The converted string.
+ *
+ * @example
+ * const convertedStr1 = lowerCase('fred') // returns 'fred'
+ * const convertedStr2 = lowerCase('Fred') // returns 'fred'
+ * const convertedStr3 = lowerCase('FRED') // returns 'fRED'
+ */
+declare function lowerFirst<T extends string = string>(str?: T): Uncapitalize<T>;
+//#endregion
+export { lowerFirst };