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-kubernetes-on-cloud/SKILL.md

@@ -1,17 +1,27 @@
 ---
 name: securing-kubernetes-on-cloud
-description: >
-  This skill covers hardening managed Kubernetes clusters on EKS, AKS, and GKE by
-  implementing Pod Security Standards, network policies, workload identity, RBAC
-  scoping, image admission controls, and runtime security monitoring. It addresses
-  cloud-specific security features including IRSA for EKS, Workload Identity for
-  GKE, and Managed Identities for AKS.
+description: 'This skill covers hardening managed Kubernetes clusters on EKS, AKS, and GKE by implementing Pod Security Standards,
+  network policies, workload identity, RBAC scoping, image admission controls, and runtime security monitoring. It addresses
+  cloud-specific security features including IRSA for EKS, Workload Identity for GKE, and Managed Identities for AKS.
+
+  '
 domain: cybersecurity
 subdomain: cloud-security
-tags: [kubernetes-security, eks, aks, gke, pod-security-standards, container-runtime]
+tags:
+- kubernetes-security
+- eks
+- aks
+- gke
+- pod-security-standards
+- container-runtime
 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 Kubernetes on Cloud