- Added `series-world.repo.ts` to handle database operations related to series worlds and their elements.
- Implemented `series-sync.repo.ts` for managing synchronization between books and series.
- Expanded `spell.ipc.ts` data models to include `seriesSpellId` for spell synchronization.
- Refactored `insertSpellTag` method in `spelltag.repo.ts` for improved error handling and logic clarity.
