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-zero-trust-in-cloud/SKILL.md

@@ -1,17 +1,27 @@
 ---
 name: implementing-zero-trust-in-cloud
-description: >
-  This skill guides organizations through implementing zero trust architecture in cloud
-  environments following NIST SP 800-207 and Google BeyondCorp principles. It covers
-  identity-centric access controls, micro-segmentation, continuous verification, device
-  trust assessment, and deploying Identity-Aware Proxy to eliminate implicit network
-  trust in AWS, Azure, and GCP environments.
+description: 'This skill guides organizations through implementing zero trust architecture in cloud environments following
+  NIST SP 800-207 and Google BeyondCorp principles. It covers identity-centric access controls, micro-segmentation, continuous
+  verification, device trust assessment, and deploying Identity-Aware Proxy to eliminate implicit network trust in AWS, Azure,
+  and GCP environments.
+
+  '
 domain: cybersecurity
 subdomain: cloud-security
-tags: [zero-trust, beyondcorp, identity-aware-proxy, micro-segmentation, continuous-verification]
+tags:
+- zero-trust
+- beyondcorp
+- identity-aware-proxy
+- micro-segmentation
+- continuous-verification
 version: 1.0.0
 author: mahipal
 license: Apache-2.0
+nist_csf:
+- PR.IR-01
+- ID.AM-08
+- GV.SC-06
+- DE.CM-01
 ---
 
 # Implementing Zero Trust in Cloud