Improve UX for "auto add screenshot"

I love the auto-add screenshot function - but I think it could use some UX smoothing:
- [x] When taking a screenshot, send a notification that users can click to see their screenshot in the desktop UI
- [x] Right clicking a file in the desktop ui should also pop open it's option menu (to share, download, etc)
- [ ] Have a step between keyboard shortcut and selecting what to screenshot (full desktop, active window, choose selection) - otherwise I might accidentally screenshot and start providing something confidential! Right now if you have two windows it screenshots both - which is super unexpected IMHO
- [ ] I get a 524 (or worse, an infinite loading screen) when trying to "share" and view a screenshot I just took on the ipfs or cloudflare gateways -- I think this might be a wider gateway issue - but FYI this makes that feature unusable (@eefahy)

I bet these are probably shared desktop/webUI items - but found them in this context so figured I'd surface them here. =] Great work! Looking forward to becoming a regular user of this feature