The router is the default entry point. Invoke it explicitly in a session:
Use $python-router to plan this Python task.
The router resolves the task to the smallest useful follow-on skill; each skill
loads only its own SKILL.md until a reference is needed. Avoid loading more
than one language skill and one domain or quality skill in the same turn.
For a known pressure point, call the skill directly:
Use $python-types-and-apis to review this `ParamSpec` decorator for
type-checker friendliness.