scroll_to_row walked all GTK children via first_child/next_sibling to count rows. The count is already available in LazyLoadState, so use that directly. Eliminates O(n) widget traversal per arrow key.
scroll_to_row walked all GTK children via first_child/next_sibling to count rows. The count is already available in LazyLoadState, so use that directly. Eliminates O(n) widget traversal per arrow key.