Raycast-like Update Flow

[tmm]

Sparkle works great, but could be cool to have a similar update flow to Raycast, where updates are downloaded in the background and there is some first-class interface for viewing release notes.

[mitchellh]

I believe Sparkle lets you customize all of this. It's a bit of a burden because you have to implement a number of different views but I think we can continue to use Sparkle and do this.

On one hand, I'm very supportive of this, I think a less intrusive update flow is great. On the other hand, the Sparkle flow I've found is very familiar and inspires some confidence in people. Raycast is a bit unique because it doesn't generally have a UI up so a pop-up popping up would be very intrusive. With Ghostty we have a window that is focused so it feels less so.