Handler for `POST /api/v1/sessions/:id/fork`, fork a session.
POST/api/v1/sessions/:id/fork
Creates a new child session that copies the parent history up to up_to_index
messages. When up_to_index is omitted, the full history is copied.
Returns the new child [SessionInfo] with HTTP 201.
Request
Responses
- 201
- 404
- 503
Child session created
Session not found
Chat subsystem unavailable