Function toolbar_reactive 

pub fn toolbar_reactive(builder: impl Fn() -> Vec<ToolbarEntry> + 'static)

toolbar that re-lowers and re-installs whenever a reactive read inside builder changes — a locale switch, or a command list that depends on what is selected.

Each pass replaces the previous one’s bindings and closures. Because a replace rebuilds the whole bar, keep per-value changes off this path: bind a toggle’s signal, bind a search field’s signal, and use ToolbarEntry::enabled_when, all of which patch a single item instead.