feat: add skill-security-auditor POWERFUL-tier skill (#230)
Security audit and vulnerability scanner for AI agent skills before installation.
Scans for:
- Code execution risks (eval, exec, os.system, subprocess shell injection)
- Data exfiltration (outbound HTTP, credential harvesting, env var extraction)
- Prompt injection in SKILL.md (system override, role hijack, safety bypass)
- Dependency supply chain (typosquatting, unpinned versions, runtime installs)
- File system abuse (boundary violations, binaries, symlinks, hidden files)
- Privilege escalation (sudo, SUID, cron manipulation, shell config writes)
- Obfuscation (base64, hex encoding, chr chains, codecs)
Produces clear PASS/WARN/FAIL verdict with per-finding remediation guidance.
Supports local dirs, git repo URLs, JSON output, strict mode, and CI/CD integration.
Includes:
- scripts/skill_security_auditor.py (1049 lines, zero dependencies)
- references/threat-model.md (complete attack vector documentation)
- SKILL.md with usage guide and report format
Tested against: rag-architect (PASS), agent-designer (PASS), senior-secops (FAIL - correctly flagged eval/exec patterns).
Co-authored-by: Leo <leo@openclaw.ai>