Skill follow-up: testcontainers-integration-tests

## Summary
Address the follow-up actions for the testcontainers-integration-tests skill as identified in the skills review.

## Acceptance Criteria
- [ ] Add sample CI run logs and a checklist for container lifecycle correctness.

## Scope
- Applies to `skills/testcontainers-integration-tests/`
- Derived from skills-review.md (commit 9c59dbc)

## Parent
- Refs: #297
