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-rbac-hardening-for-kubernetes/SKILL.md

@@ -1,12 +1,26 @@
 ---
 name: implementing-rbac-hardening-for-kubernetes
-description: Harden Kubernetes Role-Based Access Control by implementing least-privilege policies, auditing role bindings, eliminating cluster-admin sprawl, and integrating external identity providers.
+description: Harden Kubernetes Role-Based Access Control by implementing least-privilege policies, auditing role bindings,
+  eliminating cluster-admin sprawl, and integrating external identity providers.
 domain: cybersecurity
 subdomain: container-security
-tags: [kubernetes, rbac, access-control, least-privilege, security-hardening, iam, oidc, service-accounts]
-version: "1.0"
+tags:
+- kubernetes
+- rbac
+- access-control
+- least-privilege
+- security-hardening
+- iam
+- oidc
+- service-accounts
+version: '1.0'
 author: mahipal
 license: Apache-2.0
+nist_csf:
+- PR.PS-01
+- PR.IR-01
+- ID.AM-08
+- DE.CM-01
 ---
 
 # Implementing RBAC Hardening for Kubernetes