Add data/skill/SKILL.md in the agent-skills open format: a skill
directory that agents (Claude Code, Codex, OpenCode, ...) discover and
load on demand. It documents the shared option surface, the pull,
chlog, build, deb, lint, put workflow and the flags that keep runs
non-interactive; the command reference was generated from the live
--help output of every subcommand.
It lives under data/ so a later module can embed it and ship it with
the binary, for example a 'pkh skill' installer writing it into the
agent skill directories.
