Complete keyed caller content with optional bounded render-time presentation.

Requires a stable id and keyed item slots. as: :div (default) renders ordinary div wrappers, not an inferred list; :ul / :ol use native li items. Item slots accept class and unrelated rest globals and preserve trusted HEEx links/forms in document order. No content is cloned.

Effect defaults to :none, with opt-in :fade / :rise. Preset :quick uses 150ms duration and 50ms intervals; :default uses 250ms and 75ms. Only items whose delay plus duration fits in 1000ms animate; excess items immediately retain their baseline. Content starts visible (never opacity zero), focus cancels the effect, and removing styles restores fully visible content.

Motion :none, ancestor data-shadcn-motion="reduce" and OS reduced motion override effects. Finite work may finish offscreen. There is no observer, viewport-enter trigger, persistent replay tracking or animation-once guarantee. Rendering/replacement or removing and restoring suppression can replay CSS; callers own patch boundaries, native form values and any restoration.