/requirement

Deep dive on specific PCI DSS requirement

# PCI DSS Requirement Details

Provides detailed guidance on specific PCI DSS v4.0.1 requirements.

## Arguments
- `$1` - Requirement number (required: 1-12 or specific like 3.4.2)
- `$2` - Focus area (optional: controls, testing, evidence)

## Requirements Overview

| Req | Title | Key Focus |
|-----|-------|-----------|
| 1 | Network Security Controls | Firewalls, network segmentation |
| 2 | Secure Configurations | Hardening, defaults, inventory |
| 3 | Protect Stored Data | Encryption, retention, PAN masking |
| 4 | Cryptography in Transit | TLS, secure transmission |
| 5 | Malware Prot...