Add a CLI for scripting usage queries

[tifandotme]

Hi, thanks for OpenUsage.

I currently maintain custom shell scripts in my dotfiles for Claude and Codex usage, and I’d like to replace them with an OpenUsage CLI if one existed:

https://github.com/tifandotme/dotfiles/blob/master/dot_config/raycast/scripts/executable_codex_usage.sh

A small CLI would let me use OpenUsage directly in scripting contexts like Raycast, SketchyBar, cron, and similar tools.

Suggested shape

• openusage usage
• openusage usage claude
• openusage usage codex --json

or something similar.

Useful output

• JSON for scripts
• plain text for terminals
• exit codes for missing data or errors

This seems like a natural fit alongside the existing local HTTP API.

If this is already supported, I’d appreciate a pointer.