The script used authorization code flow (response_type=code) which produces
tokens expiring in ~4 hours, while the app uses implicit flow (~60 days).
Switched the script to implicit flow to match, removing the client_secret
requirement and token exchange step.
Also fixed UnauthorizedInterceptor swallowing 401 errors without calling
handler.reject(), which left Dio request Futures hanging forever.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
