v2.9.0

• On first launch (and every launch until accepted), the app now shows a disclaimer explaining
  that catalog homebrew comes from community sources not individually vetted by the developer,
  and that installing it is done at your own risk. Declining closes the app without saving
  acceptance, so it's shown again next time; nothing else runs until it's accepted.
• Downloads and Likes now show "Unavailable" instead of "0" when there's no real count for an
  entry, instead of displaying a number that could be mistaken for an actual zero.