Stop finding out you're rate-limited mid-task. Check the headroom first. One sentence from a Show HN thread stuck with me: "Thing I'd want surfaced is per account rate limit headroom before I dispatch, not after I'm stuck mid task." blackbox-bill v0.3.0 does exactly that. It was a post-mortem tool — it read your AI coding bill and explained why it looked wrong. Now it's also a pre-flight tool: it shows per-account quota headroom before you dispatch the next task, and tells you which...