Model: add sx_content column to Post. Writer: accept sx_content in create_post, create_page, update_post. Routes: read sx_content from form data in new post, new page, and edit routes. Read pipeline: ghost_db includes sx_content in public dict, detail/home views prefer sx_content over html when available, PostDTO includes sx_content. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>