chore: release v4.0.0 - sync 550+ skills and restructure docs

skills/security-requirement-extraction/SKILL.md

@@ -0,0 +1,33 @@
+---
+name: security-requirement-extraction
+description: Derive security requirements from threat models and business context. Use when translating threats into actionable requirements, creating security user stories, or building security test cases.
+---
+
+# Security Requirement Extraction
+
+Transform threat analysis into actionable security requirements.
+
+## Use this skill when
+
+- Converting threat models to requirements
+- Writing security user stories
+- Creating security test cases
+- Building security acceptance criteria
+- Compliance requirement mapping
+- Security architecture documentation
+
+## Do not use this skill when
+
+- The task is unrelated to security requirement extraction
+- You need a different domain or tool outside this scope
+
+## Instructions
+
+- Clarify goals, constraints, and required inputs.
+- Apply relevant best practices and validate outcomes.
+- Provide actionable steps and verification.
+- If detailed examples are required, open `resources/implementation-playbook.md`.
+
+## Resources
+
+- `resources/implementation-playbook.md` for detailed patterns and examples.