Function handle_ui_browser_eval 

pub(crate) async fn handle_ui_browser_eval(
    __arg0: State<AppState>,
    caller: Option<Extension<Caller>>,
    __arg2: Json<UiBrowserEvalRequest>,
) -> impl IntoResponse

POST /api/v1/ui/browser/eval — backs BrowserEval. Returns the host’s {result, type, exception} shape verbatim under data, same passthrough pattern handle_ui_query uses for matches.