Three modes:
- list: show all nav items, filterable by section
- check: validate consistency (duplicate hrefs, missing page functions,
components without nav entries)
- add: scaffold new article (component file + page function + nav entry)
Scans nav-data.sx, page-functions.sx, and all .sx component files.
Prevents the class of bugs where nav entries, page functions, and
component definitions get out of sync.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>