Arvados

Add an flag to arv-mount that means "add a prefix to each directory name inside the mount that tells you what type of object this is in Arvados."

Consider adding options to customize the strings used for these prefixes by type (could be a separate follow-up ticket).

Think very carefully about what the default prefix strings should be. Consider clarity, shell usability (are there metacharacters that need to be escaped?), how the prefixes sort, length, etc.

Consider whether the flag should be on by default in some specific circumstance like stdin isatty.

This would make arv-mount a little more comfortable for people browsing it interactively:

• When sorting contents by name (a la ls etc.), the listing will naturally be grouped by type, giving it a presentation closer to Workbench.
• Users can easily list all entries of a given type with a simple glob.

This comes at the cost of making directories more difficult to manipulate, in ways that will probably break scripts and other noninteractive use. You can no longer mkdir foo && cd foo, you have to mkdir foo && cd PREFIXfoo, stuff like that. But none of that affects a user who's only reading the mount, so there are use cases where it's pure upside.