Introduce an autoRequest boolean on Goodreads and Hardcover shelves (default true) so users can pause/resume automatic request creation. Schema, API handlers, hooks and types were updated to accept and persist autoRequest when creating or updating shelves; add endpoints only trigger an immediate resync when the feed/token changes. The shelf sync core and service code now respect autoRequest (skipping request creation and annotating logs when disabled). UI updates include an AddShelf toggle, manage/update payload changes, shelf list props, and visual indicators + toggle actions in the shelf cards.
When decrypting a user's API token fails, increment stats.errors and continue to the next shelf instead of proceeding. This ensures failed decryptions are tracked in metrics and prevents attempting to fetch data with an invalid token.
Introduce Hardcover provider support and consolidate per-provider book mapping tables into a unified BookMapping model. Adds two Prisma migrations (add_hardcover_shelves, unify_book_mappings), new backend services (hardcover-api, shelf-sync-core), and provider-specific sync logic and API routes for hardcover shelves with token/list validation. Frontend: new HardcoverForm component, refactor AddShelfModal to support Hardcover, hook updates, and small UI/accessibility tweaks. Also add documentation for Goodreads and Hardcover sync flows and update tests to cover scheduler/prisma helpers.