Conversations Retrieve

Retrieve, update, or delete a single conversation. GET /agents/conversations/<pk>/ — conversation + message tree PATCH /agents/conversations/<pk>/ — update title DELETE /agents/conversations/<pk>/ — hard delete (CASCADE removes messages) GET query params: branch_tip (str, optional): Message ID to walk from when reconstructing the active branch. If omitted, defaults to the most recent message. Messages not on the active branch are returned in ``orphaned_messages``.