- Introduced identity management features, including user and workspace context handling.
- Added `IdentityService` for orchestrating user identity and workspace management.
- Created domain entities and repository protocols for `User` and `Workspace`.
- Implemented SQLAlchemy repositories for user and workspace persistence.
- Enhanced gRPC interceptors to propagate identity context across RPC calls.
- Updated application services to integrate identity management into existing workflows.
All quality checks pass.