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/string/capitalize.mjs

@@ -0,0 +1,17 @@
+//#region src/string/capitalize.ts
+/**
+* Converts the first character of string to upper case and the remaining to lower case.
+*
+* @template T - Literal type of the string.
+* @param str - The string to be converted to uppercase.
+* @returns The capitalized string.
+*
+* @example
+* const result = capitalize('fred') // returns 'Fred'
+* const result2 = capitalize('FRED') // returns 'Fred'
+*/
+function capitalize(str) {
+	return str.charAt(0).toUpperCase() + str.slice(1).toLowerCase();
+}
+//#endregion
+export { capitalize };