Medusa Storefront Development Frontend integration guide for building storefronts with Medusa. Covers SDK usage, React Query patterns, and calling custom API routes. When to Apply Load this skill for ANY storefront development task, including: - Calling custom Medusa API routes from the storefront - Integrating Medusa SDK in frontend applications - Using React Query for data fetching - Implementing mutations with optimistic updates - Error handling and cache invalidation Also load building-with-medusa when: Building the backend API routes that the storefront calls CRITICAL: Load Reference Fil…