Agent Skills: security-threat-model

Use when designing or reviewing systems handling sensitive data (PII, PHI, financial, auth credentials), building features with security implications (auth, payments, file uploads, APIs), preparing for security audits or compliance (PCI, HIPAA, SOC 2), investigating security incidents, integrating third-party services, or when user mentions "threat model", "security architecture", "STRIDE", "trust boundaries", "attack surface", or "security review".