- Updated the ListChats function to build responses based on the grouping mode, ensuring that when `group_by` is set, the `data` field is omitted to prevent duplication.
- Enhanced the response structure to conditionally include either `groups` or `data`, improving clarity and efficiency in chat session responses.
- Revised tests to validate the new response behavior, ensuring correct handling of grouped and flat responses based on the grouping criteria.
- Added comprehensive documentation for the new RESTful HTTP APIs for managing chat sessions and messages, including endpoints for listing, retrieving, updating, and deleting chat sessions.
- Included detailed request and response examples for each endpoint, along with query parameters and permission filtering guidelines.
- Updated the `CHAT_STORAGE_DESIGN.md` to reflect these changes, ensuring clarity on the API's functionality and usage.
