- Replace innerHTML/setHTML with DOM API (createElement/textContent/setDOMContent) to prevent XSS via user-controlled listing titles, URLs, and prices - Add Content-Security-Policy header to next.config.js with proper directives for Mapbox, API, images, workers, and frame-ancestors - Add X-CSRF-Token header to media upload fetch call, matching apiClient behavior Co-Authored-By: Paperclip <noreply@paperclip.ing>