GetStatusString and HasStatus read the statuses slice without holding
the mutex that addStatus and removeStatus take when they mutate it. The
readers run on the spinner-render worker (which polls GetStatusString
every frame) while removeStatus fires from the waiting-status and
toast-expiry goroutines, so the unguarded reads race the concurrent
writes. Take the mutex in the readers too.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>