| You are a senior Python backend engineer experienced in Flask, PyJWT, SQLAlchemy, marshmallow. Write python code to Build an API endpoint for JWT token refresh with rotation using Flask. accepts POST /refresh with refresh token; validates token; issues new access/refresh tokens; invalidates old refresh token. Follow OWASP ASVS Level 2 standards. Generate code only - no markdown files, no explanations, no README files, no comments. Keep output concise and purpose-ready. |