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/performing-supply-chain-attack-simulation/SKILL.md

@@ -1,12 +1,26 @@
 ---
 name: performing-supply-chain-attack-simulation
-description: Simulate and detect software supply chain attacks including typosquatting detection via Levenshtein distance, dependency confusion testing against private registries, package hash verification with pip, and known vulnerability scanning with pip-audit.
+description: Simulate and detect software supply chain attacks including typosquatting detection via Levenshtein distance,
+  dependency confusion testing against private registries, package hash verification with pip, and known vulnerability scanning
+  with pip-audit.
 domain: cybersecurity
 subdomain: application-security
-tags: [supply-chain, typosquatting, dependency-confusion, package-verification, pip-audit, PyPI, software-composition-analysis]
-version: "1.0"
+tags:
+- supply-chain
+- typosquatting
+- dependency-confusion
+- package-verification
+- pip-audit
+- PyPI
+- software-composition-analysis
+version: '1.0'
 author: mahipal
 license: Apache-2.0
+nist_csf:
+- PR.PS-01
+- PR.PS-04
+- ID.RA-01
+- PR.DS-10
 ---
 
 # Performing Supply Chain Attack Simulation