- Add navbar with login/logout, search form, and Find Link branding
- Clean up index page: search-only, examples behind ?debug=1
- Improve article page: remove debug clutter, named Wikipedia links, collapsible candidates
- Add SVG favicon (🔗 emoji)
- Fix diff CSS: compact layout, auto table layout to eliminate wide marker column gap
- Catch TokenRequestDenied in OAuth start and show error page
- Store username in session at login; clear bad session on API failure
- Raise NoMatch when diff is empty (edit already applied)
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
