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/securing-serverless-functions/SKILL.md

@@ -1,17 +1,27 @@
 ---
 name: securing-serverless-functions
-description: >
-  This skill covers security hardening for serverless compute platforms including AWS
-  Lambda, Azure Functions, and Google Cloud Functions. It addresses least privilege IAM
-  roles, dependency vulnerability scanning, secrets management integration, input
-  validation, function URL authentication, and runtime monitoring to protect against
-  injection attacks, credential theft, and supply chain compromises.
+description: 'This skill covers security hardening for serverless compute platforms including AWS Lambda, Azure Functions,
+  and Google Cloud Functions. It addresses least privilege IAM roles, dependency vulnerability scanning, secrets management
+  integration, input validation, function URL authentication, and runtime monitoring to protect against injection attacks,
+  credential theft, and supply chain compromises.
+
+  '
 domain: cybersecurity
 subdomain: cloud-security
-tags: [serverless-security, aws-lambda, azure-functions, function-hardening, supply-chain]
+tags:
+- serverless-security
+- aws-lambda
+- azure-functions
+- function-hardening
+- supply-chain
 version: 1.0.0
 author: mahipal
 license: Apache-2.0
+nist_csf:
+- PR.IR-01
+- ID.AM-08
+- GV.SC-06
+- DE.CM-01
 ---
 
 # Securing Serverless Functions