feat(agents): in-repo np interaction instructions

Amolith created

Tell the agents how to interact with `np` when they're in this repo.
I've noticed they try to test dev changes with the installed version and
update their normal lists with the dev version. Hopefully this helps
resolve that.

Change summary

AGENTS.md | 7 +++++++
1 file changed, 7 insertions(+)

Detailed changes

AGENTS.md 🔗

@@ -15,6 +15,13 @@ Guidance for AI coding agents working in this repository. Document only reflects
 - Module path: `git.secluded.site/np`
 - Binary name: `np`
 
+**Note:** a stable, usable version of `np` is already in your PATH. If
+you're Codex, you need to escalate and ask user permission to run `np`
+commands. If you're another coding agent like Crush or Amp or Claude
+Code or Cursor, just execute `np` as a normal shell command. To use the
+development build against the user's stable database (BE CAREFUL ABOUT
+MIGRATIONS!) run `task build`, then execute `./np`.
+
 ## Development Commands (Taskfile)
 
 - Format: `task fmt` (installs and runs gofumpt)