brief open-sources a single-binary CLI that briefs AI coding agents on project toolchains

@DanKornas ships brief (github.com/git-pkgs/brief): an MIT single-binary CLI for contributors and AI coding agents that detects language, package manager, test/build/lint/formatter conventions; accepts local paths, Git URLs, and registry packages; can narrow reports to changed files; emits human or JSON output; and adds inspection commands for native artifacts, tooling gaps, and threat categories.