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-ot-incident-response-playbook/SKILL.md

@@ -1,16 +1,29 @@
 ---
 name: implementing-ot-incident-response-playbook
-description: >
-  Develop and implement OT-specific incident response playbooks aligned with
-  SANS PICERL framework, IEC 62443, and NIST SP 800-82 that address unique ICS
-  challenges including safety-critical systems, limited downtime tolerance, and
+description: 'Develop and implement OT-specific incident response playbooks aligned with SANS PICERL framework, IEC 62443,
+  and NIST SP 800-82 that address unique ICS challenges including safety-critical systems, limited downtime tolerance, and
   coordination between IT SOC, OT engineering, and plant operations teams.
+
+  '
 domain: cybersecurity
 subdomain: ot-ics-security
-tags: [ot-security, ics, incident-response, playbook, sans, iec62443, nist, safety-critical]
-version: "1.0"
+tags:
+- ot-security
+- ics
+- incident-response
+- playbook
+- sans
+- iec62443
+- nist
+- safety-critical
+version: '1.0'
 author: mahipal
 license: Apache-2.0
+nist_csf:
+- PR.IR-01
+- DE.CM-01
+- ID.AM-05
+- GV.OC-02
 ---
 
 # Implementing OT Incident Response Playbook