Skill follow-up: pair-programming

## Summary
Address the follow-up actions for the pair-programming skill as identified in the skills review.

## Acceptance Criteria
- [ ] Add a minimal pairing mode and explicit ÔÇ£handoff recordÔÇØ template.

## Scope
- Applies to `skills/pair-programming/`
- Derived from skills-review.md (commit 9c59dbc)

## Parent
- Refs: #297
