0.6.0 could not play audio in an installed build. The app's security
policy did not permit an audio source, so playback was blocked, and the
waveform was blocked separately for the same reason. Neither shows up during
development, where the app loads from a local server and the policy never
applies — which is how 0.6.0 shipped with its headline feature broken.
Sounds now load when you select one, rather than on first play.
The sound list shows a spinner while it builds its name index on first use,
instead of appearing empty.