The video element now runs the same interactive tail as containers (tooltip, on-click, swallow-clicks), extracted as finish_interactive, so tiles can be click targets without a wrapper div. Components mirror the window fullscreen state into 'window-fullscreen each render and honour the new one-shot (fullscreen! bool) builtin there, where the platform window is reachable; the request slot is consumed on use so an OS-initiated exit never fights a stale desire. The prelude gains two pure composites: (tab-row active tabs on-pick) and (modal ww wh w h on-dismiss children...), the documented sibling-scrim + swallow-clicks overlay pattern in helper form. The hello example learns the UiConfig video_frames field it was missing. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>