async fn preview_post_completions(
course_instance_id: Path<Uuid>,
pool: Data<PgPool>,
user: AuthUser,
payload: Json<TeacherManualCompletionRequest>,
) -> ControllerResult<Json<ManualCompletionPreview>>
async fn preview_post_completions(
course_instance_id: Path<Uuid>,
pool: Data<PgPool>,
user: AuthUser,
payload: Json<TeacherManualCompletionRequest>,
) -> ControllerResult<Json<ManualCompletionPreview>>