chore(release): 6.10.1

[sandstream]

Release prep for v6.10.1.

Summary:

• bump root package and lockfile from 6.10.0 to 6.10.1
• add CHANGELOG.md section for 6.10.1
• regenerate contracts/kit.opencli.json with 6.10.1 metadata

Verification:

• npm run build
• npm run lint
• npm test
• node --test dist/changelog-section.test.js dist/opencli.test.js
• node dist/cli.js --version
• node dist/cli.js self-audit --format json
• node dist/cli.js check --category security --json
• node dist/cli.js adr check
• git diff --check

[github-actions]

✅ Docker image built successfully

• CLI image: docker.io/sandstream/kit:test