Step-by-step SKILL.md packages an AI follows for a single kind of task.
A skill is a focused playbook - instructions, examples and constraints - that makes any model reliable at one job, from SQL reporting to changelog writing. The router fills a plan's skill slot with the best match for the request.
Runnable specifications live under `tests/specs/`. Every test has exactly one `Contract:<name>` and one `Env:<name>` tag. Physical owner paths mirror the production capability without logical aliases:
