Add folder anatomy (scripts/agent.py + references/api-reference.md) for 648 cybersecurity skills

Complete skill folder anatomy across all cybersecurity skills:
- scripts/agent.py: 80-150 line Python agents using real libraries (impacket,
  boto3, azure-mgmt-*, kubernetes, pefile, yara, scapy, shodan, stix2, etc.)
- references/api-reference.md: real API documentation with method signatures
- LICENSE: MIT license for all skill folders

skills/performing-access-review-and-certification/references/api-reference.md

@@ -0,0 +1,40 @@
+# API Reference: Access Review and Certification
+
+## CSV Input Format
+```csv
+username,entitlement,application,manager,status,last_used,risk_score
+jsmith,Admin,SAP,mjones,active,2025-01-15T00:00:00Z,8
+```
+
+## SoD Rules JSON Format
+```json
+[{"name": "Finance SoD", "role_a": "AP_Approver", "role_b": "AP_Creator"}]
+```
+
+## Key Review Checks
+| Check | Description | Severity |
+|-------|-------------|----------|
+| Orphaned accounts | No manager or terminated status | HIGH |
+| SoD violations | Conflicting entitlements held | CRITICAL |
+| Excessive access | Entitlement count above threshold | MEDIUM |
+| Stale entitlements | Unused beyond retention period | MEDIUM |
+
+## Compliance Frameworks
+| Framework | Requirement |
+|-----------|-------------|
+| SOX Section 404 | Periodic access reviews for financial systems |
+| SOC 2 CC6.1 | Logical access controls and reviews |
+| HIPAA 164.312(a) | Access authorization and review |
+| PCI DSS 7.2 | Restrict access based on need-to-know |
+
+## Review Campaign Design
+| Parameter | Best Practice |
+|-----------|---------------|
+| Frequency | Quarterly for privileged, semi-annual for standard |
+| Reviewer | Direct manager + application owner |
+| Escalation | Auto-revoke if no response within 14 days |
+| Evidence | Export decisions with timestamps and reviewer ID |
+
+## References
+- NIST SP 800-53 AC-6: https://csrc.nist.gov/publications/detail/sp/800-53/rev-5/final
+- ISACA Access Review: https://www.isaca.org/