Split button with default "Export GPX" (track only) and dropdown:
- Export Route: clean track for use in any app
- Export Plan: track + waypoints + no-go areas in GPX extensions
(trails:planning namespace) for reimporting into the planner
Also:
- Add no-go area serialization to generateGpx (GPX extensions)
- Parse no-go areas from GPX extensions on import
- Initialize no-go areas in Yjs session from imported GPX
- Save to Journal now exports track only (consistent with Export Route)
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>