Implement AbortController in ConfigContext, PDFContext, and preference sync to prevent race conditions during session changes or rapid navigation. Refactor document preview routes into shared utilities and add LRU caching for text previews to optimize memory. Update documentation for Better Auth schema ownership and migration workflows. Fix issues with Postgres system user seeding and better-sqlite3 configuration.
- Add document preview caching logic with in-memory and persisted storage.
- Implement S3 blobstore functions for managing document previews.
- Create rendering functions for PDF and EPUB cover images to JPEG format.
- Introduce database schema and functions for managing document preview metadata.
- Add unit tests for rendering PDF and EPUB previews.
- Implemented user preferences management with a new API for GET and PUT requests.
- Added user document progress tracking with a new API for retrieving and updating progress.
- Introduced database schema changes for user preferences and document progress.
- Enhanced EPUB and TTS contexts to support syncing user preferences and document progress.
- Added functions to handle transferring user preferences and progress during account linking.
- Updated client-side logic to schedule syncing of user preferences and document progress.
