Reassigns the study to the project given as projectID in the body. The target must be a non-deleted project in the same group as the study; projects shared from other groups through a project group cannot be targeted (an unknown, deleted, or cross-group projectID returns 400). The study's experiments, workflow steps, status, and meta fields move with it unchanged. Collaborators set on the study itself are kept; a study that inherits its collaborators from its project picks up the target project's collaborators (including project-group members) and loses the old project's. Existing experiment assignees are not changed, so users assigned to the study's experiments keep their access after the move. A successful move is recorded in the study's journal log; moving a study to the project it is already in changes nothing.