Generative: the video strip scrolls and reveals; tags wrap in their row

The timeline's scroll box is the flex row itself, so its reach is its
shots; a focused shot brings itself whole into view through
layout::bring_into_view, which table headers now share; Extend sits
with the caption under the strip. A voice's tags cap at the row's
width and wrap inside it.

src/layout/mod.rs

@@ -21,6 +21,7 @@ pub use floating::FloatingPanel;
 pub use grid::{Masonry, SimpleGrid};
 pub use page::{AppShell, MasterDetail, Page};
 pub use panes::{PaneGroup, PaneId, PaneLayout};
+pub(crate) use scroll::bring_into_view;
 pub use scroll::{ScrollArea, Scrollbar, on_axis};
 pub use scroll_aids::{ScrollShadow, ScrollToTop, StickyHeader};
 pub use sheet::{Drawer, Sheet};