The desktop app asks for a newer release on its first frame, and nothing
could stop it, though the README says PdfCraft works offline. A preference,
on by default so nothing changes for anyone who leaves it, keeps the app off
the network until Help ▸ Check for updates is chosen. It has its own settings
key: check_updates_at_start was an opt-in, off unless chosen, so settings
written then would turn this off unasked.