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/building-threat-intelligence-platform/SKILL.md

@@ -1,12 +1,26 @@
 ---
 name: building-threat-intelligence-platform
-description: Building a Threat Intelligence Platform (TIP) involves deploying and integrating multiple CTI tools into a unified system for collecting, analyzing, enriching, and disseminating threat intelligence. T
+description: Building a Threat Intelligence Platform (TIP) involves deploying and integrating multiple CTI tools into a unified
+  system for collecting, analyzing, enriching, and disseminating threat intelligence. T
 domain: cybersecurity
 subdomain: threat-intelligence
-tags: [threat-intelligence, cti, ioc, mitre-attack, stix, platform-building, misp, opencti]
-version: "1.0"
+tags:
+- threat-intelligence
+- cti
+- ioc
+- mitre-attack
+- stix
+- platform-building
+- misp
+- opencti
+version: '1.0'
 author: mahipal
 license: Apache-2.0
+nist_csf:
+- ID.RA-01
+- ID.RA-05
+- DE.CM-01
+- DE.AE-02
 ---
 # Building Threat Intelligence Platform