docs: ADR-0006 sigstore integration

[mrbrandao]

Summary

• Add ADR-0006 documenting sigstore bundle verification at add time using sigstore-go
• Covers enforcement matrix (warn/strict), identity derivation from GitHub repository URL, and OCI verification via skillimage pkg/oci
• Add paired design doc with verification flow Mermaid diagram, sigstore component diagram, enforcement table, and GitHub Actions signing workflow reference

Related Issues

• Relates to feat: skill signature verification at mod add time (sigstore MVP) #84 (sigstore MVP proposal)
• Relates to [FEATURE] - SKILL attestation #62 (skill attestation / nono)
• Depends on ADR-0005 (module package format — defines what gets signed)

Test Plan

• ADR follows the project template format
• Design doc Mermaid diagrams render correctly
• Enforcement matrix is consistent with issue feat: skill signature verification at mod add time (sigstore MVP) #84

AI Disclosure

AI-assisted with Claude Code

[coderabbitai]

Warning

Rate limit exceeded

@mrbrandao has exceeded the limit for the number of commits that can be reviewed per hour. Please wait 11 minutes and 23 seconds before requesting another review.

To keep reviews running without waiting, you can enable usage-based add-on for your organization. This allows additional reviews beyond the hourly cap. Account admins can enable it under billing.

⌛ How to resolve this issue?

After the wait time has elapsed, a review can be triggered using the @coderabbitai review command as a PR comment. Alternatively, push new commits to this PR.

We recommend that you space out your commits to avoid hitting the rate limit.

🚦 How do rate limits work?

CodeRabbit enforces hourly rate limits for each developer per organization.

Our paid plans have higher rate limits than the trial, open-source and free plans. In all cases, we re-allow further reviews after a brief timeout.

Please see our FAQ for further information.

ℹ️ Review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: 8adb3970-275f-4ef2-b073-cd2a23ea9ac2

📥 Commits

Reviewing files that changed from the base of the PR and between a343c6e and 4b0b8e2.

📒 Files selected for processing (2)

• docs/adr/0006-sigstore-integration.md
• docs/dev-guide/design/sigstore-integration.md

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Review rate limit: 0/1 reviews remaining, refill in 11 minutes and 23 seconds.}

_{Comment @coderabbitai help to get the list of available commands and usage tips.}

[mrbrandao]

@pavelanni, This is an initial ADR proposal for integration with skillsimage, starts with the go conversion.