add entity types, publication search, and link previews
- search now returns entity type (article, looseleaf, publication)
- publications searchable by name/description via FTS
- entity type badges in UI (colored by type)
- dynamic OG meta tags via cloudflare pages function
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>