Including a GMail sidebar gadget within an installable Google Marketplace listing

I would like to build an application that I can list on the Google Apps Marketplace so that organization administrators can install it with one-click.

The application interacts with Google through a sidebar in Gmail. I've been able to start testing this with the "Add Gadget by URL" GMail Labs feature, but now I would like to package it in an application that the admins can roll out to all their users at the same time.

Google's documentation for application manifests mentions how to add contextual gadgets, but not sidebar gadgets. Does anyone have experience adding a sidebar gadget within an application manifest?

Example of a sidebar that I'd like to embed:

<Module>
  <ModulePrefs height="400" title="Mike's First Sidebar!">
    <Require feature="views"/>
    <Require feature="dynamic-height"/>
    <Require feature="settitle"/>
  </ModulePrefs>
  <Content type="html" view="home">
    <![CDATA[
      <h2>Todo:</h2>
          <ul>
             <li>Create a sidebar gadget</li>
             <li>Add it to an application</li>
             <li>List the application on the marketplace</li>
          </ul>
    ]]>
  </Content>
</Module>

The lack of documentation is simply because that isn't a supported feature.