Probably just GitHub (the browser UI). If you want to do it offline or from the command line, I understand why you might hesitate want to check out files, but stashing in git is extremely easy.
"All" might not be possible, but every Rust release tends to see improvements in lifetime elision. I just went through a few Rust apps I wrote 6 months ago and was able to get rid of nearly every explicit lifetime annotation thanks to improvements.
So there's definitely room for improvement, but also good progress being made.