How can I add actions to all folder nodes?

Register to Loaders/folder/any/Actions

Example:

@ActionID(
        category = "Build",
        id = "com.foo.bar.OnAnyFolderAction")
@ActionRegistration(
        displayName = "#CTL_OnAnyFolderAction")
@ActionReferences({
    @ActionReference(path = "Loaders/folder/any/Actions", position = 0)
})
@Messages("CTL_OnAnyFolderAction=ActionOnAnyFolder")
public final class OnAnyFolderAction implements ActionListener {

    private final DataFolder context;

    public OnAnyFolderAction(DataFolder context) {
        this.context = context;
    }

    @Override
    public void actionPerformed(ActionEvent ev) {
        JOptionPane.showMessageDialog(null, context.toString());
    }
}