Announce to unactivated users

Email users who hold a license but haven't activated a machine yet — a nudge to get started (or offer a hand). Send a test to yourself first.

Announce to all owners

Email everyone who owns BassMuse (any active paid license, activated or not) — e.g. a new release. Send a test to yourself first.

Add an "Update BassMuse" button (turn off if the download links are already in the message)