- Introduced optional LanceDB vector store for semantic search, configurable via environment variables.
- Updated `.env.example` and `Cargo.toml` to include LanceDB settings.
- Enhanced `DatabaseConfig` to support vector backend selection and LanceDB path configuration.
- Implemented `VectorBackend` enum to manage vector store options.
- Added functionality to connect to LanceDB in the database connection logic.
- Updated relevant documentation to reflect new features and configuration options.
This change allows users to leverage LanceDB as an alternative to pgvector/libsql for improved search capabilities.
