A placed image may name the picture it shows (assetId, Hive field 11);
without one, its own id names the picture, as before, so every image,
.ica file and backup made so far reads exactly as it did. pictureId is
the id the picture is stored, uploaded and found under: rendering, the
page transition, screenshots, video export, the upload queue, cloud
export, local-to-cloud migration and the cleanup of unused picture
files all use it. Item identity (undo, transitions, sync rows, hero
tags) stays the image's own id.

Nothing makes such images yet; copies will (see the server half).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>