- Detect mermaid/plantuml/drawio/mxgraph code fences as 'diagram' sub-blocks
- Render via local servers (PlantUML :8080, Mermaid :8081, draw.io :8082)
- Fall back to CLI tools (plantuml, mmdc, drawio) if servers unavailable
- Cache rendered SVGs in ~/.cache/*/diagrams/ keyed by content hash
- Show rendered image with white background (dark theme friendly)
- Collapsible source toggle (▶/▼) below rendered diagram
- Middle-click to invalidate cache and re-render
- Left-click opens fullscreen pannable/zoomable viewer
- Fullscreen: scroll-wheel zoom, drag to pan, Esc/right-click/dbl-click to close
- Both kf5 and kf6 builds
29c74b2837
