persist.serializer

Live-state serializer driver for persist — the play-mode half of the scene-save story. scene_saver.serializeEntity already turns a live entity into the v6 per-entity body, but it is only ever fed ids from the edit-mode dirty-mark queue (empty in play). This driver supplies the play-mode side: it enumerates the active layer's live entities, filters them by provenance (execute-origin only, via persist.origin) and authored-ness (scene_saver's spawner-managed / temporary filter), and assembles a loadable v6 scene body.

Lighting stays entity-primary: it comes from Light components on the live entities, not from a separate lighting block.