- Extract markdown + bare URLs from assistant messages, deduplicate, show in new Links tab
- Add tab switcher (Artifacts / Links) with counts in header
- Add copy-all and open-all link actions
- Full style migration to gnexus-ui-kit palette:
  - surface-page #16161E, borders 2px rgba(192,202,245,0.24)
  - accent color #FF9E64, hover/active #7AA2F7
  - tabs: uppercase, bold, border-right separators
  - list items: 2px transparent border, surface-panel-muted bg
  - action buttons: 2px border, electric-blue hover
  - zero border-radius throughout

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>