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-disk-encryption-with-bitlocker/SKILL.md

@@ -1,17 +1,28 @@
 ---
 name: implementing-disk-encryption-with-bitlocker
-description: >
-  Implements full disk encryption using Microsoft BitLocker on Windows endpoints to protect
-  data at rest from unauthorized access in case of device loss or theft. Use when deploying
-  encryption for compliance requirements, securing mobile workstations, or implementing data
-  protection controls across the enterprise. Activates for requests involving BitLocker
+description: 'Implements full disk encryption using Microsoft BitLocker on Windows endpoints to protect data at rest from
+  unauthorized access in case of device loss or theft. Use when deploying encryption for compliance requirements, securing
+  mobile workstations, or implementing data protection controls across the enterprise. Activates for requests involving BitLocker
   encryption, disk encryption, TPM configuration, or data-at-rest protection.
+
+  '
 domain: cybersecurity
 subdomain: endpoint-security
-tags: [endpoint, encryption, BitLocker, TPM, data-protection, windows-security]
+tags:
+- endpoint
+- encryption
+- BitLocker
+- TPM
+- data-protection
+- windows-security
 version: 1.0.0
 author: mahipal
 license: Apache-2.0
+nist_csf:
+- PR.PS-01
+- PR.PS-02
+- DE.CM-01
+- PR.IR-01
 ---
 # Implementing Disk Encryption with BitLocker