add a command palette

[cameronsjo]

idea / problem

I went looking for how to move a pane into a new space, and there isn't a keybinding for it.. Looks like there's a CLI command for it, but I don't want to contaminate my agent's context with the command. And another command I tried the other night didn't have the right environment variables.

I'm not really a big vim/tmux or whatever other native TUIs with the fancy chords and keybinds, I'd rather have a command palette.

Claude found #819 and #1832 but there isn't anything that combines them.

requested change

Add execution to the keybind help overlay then close the window after it's done.

why you want this

Commands palettes are easier for the not-so-power users who can't learn new tricks.

already built it

I went ahead and put it together to see if it felt right, and it does — prefix+/ opens the same overlay, typing filters it, enter runs the row. Two commits on top of eacea2d: https://github.com/cameronsjo/herdr/tree/feat/executable-keybind-help

Happy to open a PR if you want it.

[cameronsjo]

Opened #2299 with a working implementation, which ended up somewhere different
from what I proposed above.

Making the keybind reference executable turned out to be the wrong shape. Using
it surfaced a screen with two identities: tab on the plain ? reference
silently armed a row so enter opened Settings instead of closing, the footer
had to describe two modes at once, and reference-only rows sat in a list of
runnable commands with nothing to distinguish them. Most of the problems traced
back to the reuse rather than to any individual bug.

So the PR adds a separate palette on prefix+/ and leaves ? exactly as it
is. The reference's rows carry the action they describe, which is what lets the
palette source one command inventory instead of duplicating the list.

It exceeds the automated intake budget, so it will close on its own. Posting it
here so the code is reachable if the idea is worth pursuing. Happy to cut it
down, split it, or drop it on a maintainer's word.