Root cause of 'Method does not exist / The methods of the module is undefined':
Cocos 3.8 expects handlers inside a 'methods' export (plus load/unload hooks),
not flat on module.exports. Handlers receive args directly (no event); return
value is the request reply. Verified vs official 3.8 first/messages docs.
Also: menu path + panel title switched to literal strings (i18n showed 'undefined').