feat(rcart): merge group shopping into rCart module
Add shared shopping carts with URL product extraction, pooled funding,
and extension support alongside existing cosmolocal catalog/orders.
- Shopping cart schemas (ShoppingCartDoc, ShoppingCartIndexDoc)
- Server-side product extraction (JSON-LD, meta tags, Amazon/Shopify)
- 13 new API routes (cart CRUD, items, contributions, extension endpoints)
- 3-tab UI (Carts/Catalog/Orders) with cart detail, funding progress
- Local-first client subscriptions for real-time cart sync
- Updated landing page to reflect group shopping workflow
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Jeff Emmett
12d3e86e13