[jraph]

Seems nice :-)

For this part specifically:

> the all-too-familiar cycle of `ls` to view a directory, followed by `cd`, then `ls`, and repeat

I use (oh-my-)zsh for this. Tab would autocomplete (with some basic support for "fuzzy search" - case insensitive, part for the file works). If there are several options it displays them and they can be selected. When completed, another tab press displays the folder content. For some commands, it tries to show only relevant files. For cd, it won't complete with the name of a (non-folder) file.

This is very effective. I feel like one of my hands is missing when I don't have this, for instance when I'm using bash.

[dankco]

I agree! nav supports this workflow in search mode as well, and I could easily support fuzzy searching rather than exact match if that would be valuable.