Close [AI-116](https://linear.app/affine-design/issue/AI-116)
<!-- This is an auto-generated comment: release notes by coderabbit.ai -->
## Summary by CodeRabbit
- **New Features**
- Added the ability to retrieve detailed information for a specific Copilot session by its ID, including model metadata and optional models, via the user interface and API.
- Session data now includes additional fields such as the model used and a list of optional models.
- Enhanced GraphQL queries and UI components to support fetching and displaying these new session details.
- **Improvements**
- Session lists now provide richer information, including model details, for each session.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
fcc9b31da9