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/detecting-shadow-it-cloud-usage/SKILL.md

@@ -1,12 +1,25 @@
 ---
 name: detecting-shadow-it-cloud-usage
-description: Detect unauthorized SaaS and cloud service usage (shadow IT) by analyzing proxy logs, DNS query logs, and netflow data using Python pandas for traffic pattern analysis and domain classification.
+description: Detect unauthorized SaaS and cloud service usage (shadow IT) by analyzing proxy logs, DNS query logs, and netflow
+  data using Python pandas for traffic pattern analysis and domain classification.
 domain: cybersecurity
 subdomain: cloud-security
-tags: [shadow-IT, SaaS-discovery, proxy-logs, DNS-analysis, netflow, cloud-security, pandas]
-version: "1.0"
+tags:
+- shadow-IT
+- SaaS-discovery
+- proxy-logs
+- DNS-analysis
+- netflow
+- cloud-security
+- pandas
+version: '1.0'
 author: mahipal
 license: Apache-2.0
+nist_csf:
+- PR.IR-01
+- ID.AM-08
+- GV.SC-06
+- DE.CM-01
 ---
 
 # Detecting Shadow IT Cloud Usage