Function handle_ui_query 

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

POST /api/v1/ui/query — backs the UIQuery MCP tool. Returns matched elements (tag/text/attrs/rect/focused) within the caller’s own pane subtree — the same shape browser_api::types::QueryData returns.