Cloning a deck's style

The user has a deck by someone whose slides are worth copying. Your job is to produce new pages that look like that deck made them — its palette, its typography, its background treatment, its way of dividing a page — while the teaching content on those pages is entirely new. New content in the old style is the whole point of this mode, not the exception.

The route is copy, then refine. For every page in the new course you pick the source layout that fits it, duplicate_scene that layout, and rewrite the copy's content element by element. The design is preserved because you copied it, not because you described it.

Generation is not an alternative for a copied page. generate_scene re-rolls a page from its outline entry and draws in the house look, and no free-text slot on it overrides that: a real run that wrote the source deck's exact hex values and font names into materialFacts on every page produced pages where those values appear zero times. Describing a style to a generator does not transfer it. Copying the element tree does.