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-serverless-function-security-review/SKILL.md

@@ -1,15 +1,27 @@
 ---
 name: performing-serverless-function-security-review
-description: >
-  Performing security reviews of serverless functions across AWS Lambda, Azure Functions,
-  and GCP Cloud Functions to identify overly permissive execution roles, insecure environment
-  variables, injection vulnerabilities, and missing runtime protections.
+description: 'Performing security reviews of serverless functions across AWS Lambda, Azure Functions, and GCP Cloud Functions
+  to identify overly permissive execution roles, insecure environment variables, injection vulnerabilities, and missing runtime
+  protections.
+
+  '
 domain: cybersecurity
 subdomain: cloud-security
-tags: [cloud-security, serverless, lambda, azure-functions, cloud-functions, security-review]
-version: "1.0"
+tags:
+- cloud-security
+- serverless
+- lambda
+- azure-functions
+- cloud-functions
+- security-review
+version: '1.0'
 author: mahipal
 license: Apache-2.0
+nist_csf:
+- PR.IR-01
+- ID.AM-08
+- GV.SC-06
+- DE.CM-01
 ---
 
 # Performing Serverless Function Security Review