feat: add resolve-snyk skill

[cs-raj]

Summary

• Adds the resolve-snyk skill for end-to-end Snyk vulnerability resolution on any GitHub npm repo
• No hardcoded IDs or credentials — fully generic and safe to share

What the skill does

1. Preflight — verifies Snyk CLI + gh CLI are authenticated
2. Clone — clones the target repo to a temp directory
3. Audit — runs full baseline: npm audit + snyk test + snyk code
4. Plan — identifies safe upgrades (patch/minor) and transitive overrides
5. Approve — user picks exactly what to apply
6. Apply — updates package.json only (no install yet)
7. Install — single clean install after lock file + node_modules wipe (approval required)
8. Re-audit — before vs after comparison
9. Build — hard gate: does not commit if build fails
10. PR — commits and raises PR via gh (approval required)
11. Cleanup — optionally deletes the cloned temp dir

How to install

```bash
npx skills add git@github.com:contentstack/contentstack-agent-skills.git --skill resolve-snyk
```

Requirements

Tool	Install	Auth
Snyk CLI	npm install -g snyk	snyk auth
gh CLI	brew install gh	gh auth login
Node.js	nodejs.org	—

🤖 Generated with Claude Code

[github-actions]

🔒 Security Scan Results

ℹ️ Note: Only vulnerabilities with available fixes (upgrades or patches) are counted toward thresholds.

Check Type	Count (with fixes)	Without fixes	Threshold	Result
🔴 Critical Severity	0	0	10	✅ Passed
🟠 High Severity	0	0	25	✅ Passed
🟡 Medium Severity	0	0	500	✅ Passed
🔵 Low Severity	0	0	1000	✅ Passed

⏱️ SLA Breach Summary

✅ No SLA breaches detected. All vulnerabilities are within acceptable time thresholds.

Severity	Breaches (with fixes)	Breaches (no fixes)	SLA Threshold (with/no fixes)	Status
🔴 Critical	0	0	15 / 30 days	✅ Passed
🟠 High	0	0	30 / 120 days	✅ Passed
🟡 Medium	0	0	90 / 365 days	✅ Passed
🔵 Low	0	0	180 / 365 days	✅ Passed

✅ BUILD PASSED - All security checks passed