Shared Audio

So this work order is not introducing a new idea. It is closing an already-recognized architectural gap. 0.2) Production Blocking Gap Current blocker: editor-authored scene changes do not pass through a canonical mutation/history lane transform drags mutate scene state directly there is no undo stack there is no redo stack there are no transaction boundaries there is no policy for what is undoable versus transient This blocks viewport-editor widening because the next real tools will otherwise