GitHub - mukul975/Anthropic-Cybersecurity-Skills: 734+ structured cybersecurity skills for AI agents · MITRE ATT&CK mapped · agentskills.io open standard · Works with Claude Code, GitHub Copilot, OpenAI Codex CLI, Cursor, Gemini CLI & 20+ platforms · Penetration testing, DFIR, threat intel, cloud security & more · Apache 2.0 · GitHub 27/03/2026claude skills securité