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/configuring-network-segmentation-with-vlans/SKILL.md

@@ -1,15 +1,26 @@
 ---
 name: configuring-network-segmentation-with-vlans
-description: >
-  Designs and implements VLAN-based network segmentation on managed switches to isolate
-  network zones, enforce access control between segments, and reduce the attack surface
-  by limiting lateral movement paths in enterprise network environments.
+description: 'Designs and implements VLAN-based network segmentation on managed switches to isolate network zones, enforce
+  access control between segments, and reduce the attack surface by limiting lateral movement paths in enterprise network
+  environments.
+
+  '
 domain: cybersecurity
 subdomain: network-security
-tags: [network-security, vlan, network-segmentation, switch-security, 802.1q]
-version: "1.0"
+tags:
+- network-security
+- vlan
+- network-segmentation
+- switch-security
+- 802.1q
+version: '1.0'
 author: mahipal
 license: Apache-2.0
+nist_csf:
+- PR.IR-01
+- DE.CM-01
+- ID.AM-03
+- PR.DS-02
 ---
 # Configuring Network Segmentation with VLANs