wld.play

Enters play mode and leaves the gameplay simulation running. It flips engine.mode to "play" when the engine is elsewhere, and resumes the standing gameplay pause when the engine is already in play; a pause another caller holds is theirs to settle, so the call refuses and names them rather than lifting it. The flip rebuilds the scene for play over the frames after it, and the call returns once that rebuild has ended. The calling agent takes part in the play session from then on, so its /source writes land on the play shadow with the session's, to be settled when leaving play (see wld.edit).

Returns { mode, paused, resumed, settled }: the run state the call produced, and whether the simulation it met was stopped and is now running.