- 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.
- Implement `schema.ts` for SQLite schema creation, indexing, and sync metadata initialization.
- Develop `encryption.ts` with AES-256-GCM encryption utilities for securing database data.
- Add `database.service.ts` to manage CRUD operations with encryption support, user-specific databases, and schema initialization.
- Integrate book, chapter, and character operations with encrypted content handling and sync preparation.
- Removed unnecessary React imports.
- Adjusted package.json scripts for Electron integration.
- Updated components to replace Next.js-specific imports with Electron-compatible alternatives.
- Minor tsconfig.json changes for better compatibility.
