- Introduce IPC handlers in `ipc/chapter.ipc.ts` for chapter CRUD, content management, and related operations.
- Register chapter IPC module in `main.ts` for application-wide access.
- Enhance type definitions for chapter functionalities, improving code consistency.
- Refactor `ipc/book.ipc.ts` to include new `UpdateStoryData` interface and additional story update handler.
- Reorganize and reformat IPC handlers for improved readability and structure.
- Add missing type definitions for `StoryData`, `AddWorldElementData`, `SetAIGuideLineData`, and others.
- Simplify handler functions by enforcing consistent parameter usage and return types.
- Remove outdated comments, redundant logic, and placeholder TODOs.
- Introduce `db:user:sync` to synchronize user data with the local database during initialization.
- Add `db:user:info` and `db:user:update` IPC handlers for fetching and updating user information.
- Update `User` model and repository to support extended user fields and improved structure.
- Dynamically import user models in main process to avoid circular dependencies.
- Refactor database initialization in the app to include user sync logic with error handling.
- Delete `data.service.ts` and `offline-data.service.ts`, consolidating functionality into `LocalSystem`.
- Refactor book, character, and conversation operations to adopt unified, multilingual, and session-enabled IPC handlers in `LocalSystem`.
- Simplify redundant legacy methods, enhancing maintainability and consistency.
- Add `LocalSystem` with handlers for session retrieval (`userId`, `lang`) and error handling.
- Extend IPC handlers to support multilingual operations (`fr`, `en`) and session data injection
