- Cart context with pure functions for add/remove/update/hydrate
- Price formatting via ex_money (replaces all float division)
- CartHook on_mount with attach_hook for shared event handlers
(open/close drawer, remove item, PubSub sync)
- Accessible cart drawer with focus trap, scroll lock, aria-live
- Cart page with increment/decrement quantity controls
- Preview mode cart drawer support in theme editor
- Cart persistence to session via JS hook + API endpoint
- 19 tests covering all Cart pure functions
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
