Mermaid diagram rendering in the app and Quick Look.
- Fenced
mermaidcode blocks now render as diagrams. The Markdown pipeline detectsmermaidfences, swaps them for diagram containers, and runs the Mermaid renderer on load — flowcharts, sequence diagrams, class diagrams, and the rest show up inline instead of as raw code. - Renderer is bundled, so previews work offline. The Mermaid script ships inside the app bundle and is shared with the Quick Look extension; no CDN request is made when opening a document.
- Diagrams follow the system appearance. Mermaid initializes with the dark theme when the system is in dark mode and the default theme otherwise, and uses the SF system font so labels match the surrounding text.