GitHub/GitLab URIs don't contain /-/, so you can't tell where the FS should split

[jbfaden]

I made a bad choice early on that the blob and raw parts of the URLs would be removed for brevity, and this also included the slash (-). So the URI for Dave's digitizer is

https://research-git.uiowa.edu/space-physics/tracers/msc/public/-/blob/main/u/dave/20260225/digitizer.jy

but this is made canonical by making it

https://research-git.uiowa.edu/space-physics/tracers/msc/public/main/u/dave/20260225/digitizer.jy

So this makes the demarcation between the filesystem and the file ambiguous. I'd like to make it so that

https://research-git.uiowa.edu/space-physics/tracers/msc/public/-/main/u/dave/20260225/digitizer.jy

is the canonical URI, but I don't think this is a trivial change.

[jbfaden]

In the meantime, I assume that the first "main" or "master" found in the URI is the branch, see GitHubFileSystem.java.