docs(cookbook): add regulatory compliance evaluation pipeline

Add a comprehensive cookbook demonstrating how to build automated compliance
evaluation pipelines for regulated industries using Langfuse.

The cookbook covers:
- PII detection (rule-based regex patterns)
- Legal privilege detection (hybrid rule + LLM-as-a-Judge)
- Factual grounding / hallucination detection (LLM-as-a-Judge)
- Bias and fairness evaluation (LLM-as-a-Judge)
- Complete pipeline orchestration with Langfuse score ingestion
- NIST AI RMF alignment mapping

Designed for legal services, financial services, insurance, and healthcare
organisations deploying AI in regulated contexts.

https://claude.ai/code/session_011De5LfdoirAg729crpDFaF

Author: garyatwalAI