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-network-traffic-baselining/SKILL.md

@@ -1,19 +1,25 @@
 ---
 name: implementing-network-traffic-baselining
-description: Build network traffic baselines from NetFlow/IPFIX data using Python pandas for statistical analysis, z-score anomaly detection, and hourly/daily traffic pattern profiling
+description: Build network traffic baselines from NetFlow/IPFIX data using Python pandas for statistical analysis, z-score
+  anomaly detection, and hourly/daily traffic pattern profiling
 domain: cybersecurity
 subdomain: network-security
 tags:
-  - netflow
-  - ipfix
-  - traffic-analysis
-  - baselining
-  - anomaly-detection
-  - pandas
-  - network-monitoring
-version: "1.0"
+- netflow
+- ipfix
+- traffic-analysis
+- baselining
+- anomaly-detection
+- pandas
+- network-monitoring
+version: '1.0'
 author: mahipal
 license: Apache-2.0
+nist_csf:
+- PR.IR-01
+- DE.CM-01
+- ID.AM-03
+- PR.DS-02
 ---
 
 # Implementing Network Traffic Baselining