Add data retrieval helpers for SSR template rendering:
- GetDeviceMappingsData: Fetch device shelf mappings for device settings UI
- GetUserCollectionsList: Get all user collections for dropdowns and listings
- GetCollectionData: Get single collection with metadata
- GetCollectionBooksData: Get books in a collection
These functions support the Phase 9 frontend features by providing
efficient data access for template rendering without modifying
existing API endpoints.
john-okeefe
b1ca813ba4