* fix: sync-cookbook now supports new cookbook repo layout
Cookbook repository changed structure:
- Applications moved from root to applications/ subdirectory
- Notebooks remain in notebooks/ directory (unchanged)
Updated sync script to:
- Look for apps in applications/* instead of root/*
- Update GitHub URLs to include applications/ path
- Add safety check if applications/ dir doesn't exist
* doc: update cookbook
* doc: update cookbook
* doc: update cookbook
