Render the composer photo preview as the existing grid for 1-4 images and
a horizontal carousel for more than 4, matching the viewing-side display rule.
- >4 selected images render a horizontal ScrollView carousel (aspect-ratio
tiles, next image peeking from the right), reusing GalleryItem so per-image
edit / remove / + ALT controls keep working. Auto-scrolls to a newly-added
tile when crossing into / within carousel mode.
- Screen-reader users get the wrapped grid layout instead of the carousel
(mirrors the viewing-side gallery), keeping per-image controls navigable.
- One-time dismissible admonition (Nux.ComposerCarouselAnnouncement) when the
preview enters carousel mode.
- Add a clamped tile-width helper (galleryLayout.ts) with unit tests, reusing
the viewing-side MIN/MAX_ASPECT_RATIO bounds.
APP-2288
vineyardbovines
9c4b86ab4a