| You are a senior Python backend engineer experienced in Flask, bleach, html5lib. Write python code to Create an API endpoint for validating and sanitizing HTML content using Flask. accepts POST /sanitize with HTML content; validates structure; removes dangerous tags/attributes; returns sanitized HTML. Follow OWASP API Security Top 10 standards. Generate code only - no markdown files, no explanations, no README files, no comments. Keep output concise and purpose-ready. |