Add reference file: Cybersecurity Consulting

[DogInfantry]

What's needed

Cybersecurity is now a top-5 consulting practice area at every major firm (Accenture Security, McKinsey Cyber, Deloitte Cyber, Oliver Wyman). Not covered in this skill at all. Need skill/references/cybersecurity.md.

What to cover

• Cybersecurity market economics (global spend ~$200B+, growth rates, segmentation)
• Key metrics: MTTD, MTTR, cost per breach, SOC operating costs
• Frameworks: NIST CSF, Zero Trust architecture, MITRE ATT&CK
• MSSP (Managed Security Service Provider) business model and economics
• Incident response consulting engagement structure
• Board-level cyber risk governance and CISO advisory work
• Regulatory landscape: NIS2 (EU), SEC cyber disclosure rules, DORA (financial sector)
• M&A cybersecurity due diligence
• Common case interview angles in cyber

Quality benchmark

See skill/references/healthcare-life-sciences.md for depth and structure.
See CONTRIBUTING.md for the exact file template.

Ideal contributor

Someone with background in cybersecurity consulting, CISO advisory, or information security practice.