Function maximize_window 

pub fn maximize_window(
    state: &Arc<AppState>,
    args: &Value,
) -> Result<Value, String>

Maximize/unmaximize the window (toggle).

Args: { "label": string | null } — optional window label. When omitted, defaults to “main” (preserves single-window-build behavior). The frontend reads its own label from the ?windowLabel=… URL query and passes it here so non-main windows act on the right CEF window.