Function handle_ui_click 

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

POST /api/v1/ui/click — backs the UIClick MCP tool. Synthesizes a real mouse click at the first selector match within the caller’s own pane subtree.