feat: add NIST CSF 2.0 nist_csf field to all 754 cybersecurity skills

Mapped every skill to NIST CSF 2.0 subcategory IDs (GV/ID/PR/DE/RS/RC functions)
based on subdomain and content analysis. Restores 11 skills corrupted during
prior rebase, re-enriching with ATLAS, D3FEND, NIST AI RMF, and CSF 2.0 fields.

All 754 skills now carry structured mappings for all 5 security frameworks:
- MITRE ATT&CK (in tags)
- MITRE ATLAS v5.5 (atlas_techniques)
- MITRE D3FEND v1.3 (d3fend_techniques)
- NIST AI RMF 1.0 (nist_ai_rmf)
- NIST CSF 2.0 (nist_csf)

skills/implementing-secrets-scanning-in-ci-cd/SKILL.md

@@ -3,10 +3,19 @@ name: implementing-secrets-scanning-in-ci-cd
 description: Integrate gitleaks and trufflehog into CI/CD pipelines to detect leaked secrets before deployment
 domain: cybersecurity
 subdomain: devsecops
-tags: [secrets-scanning, gitleaks, trufflehog, ci-cd]
-version: "1.0"
+tags:
+- secrets-scanning
+- gitleaks
+- trufflehog
+- ci-cd
+version: '1.0'
 author: mahipal
 license: Apache-2.0
+nist_csf:
+- PR.PS-01
+- GV.SC-07
+- ID.IM-04
+- PR.PS-04
 ---