There's unfortunately no automated tool for that yet in CQ.
If you want to build something like that yourself, the best is to create a page somewhere in your site structure that isn't displayed in the navigation (you would name this page "sitemap" or "robots" - without the extention). You also need to build a custom page component for each of these two type of special pages, where you control the output to be exactly what you need (ie. no HTML in the output) - for a first version, simply hardcode the content of each in the JSPs, later, you can then make it more sophisticated (eg. reading out a page property, or iterating over your page structure). Using CRXDE Light, you obviously need to change the sling:resourceType property of your sitemap or robots page to point to the appropriate new page components.
Then to make these pages available on the root path, you can use the /etc/map settings. Such a configuration would look like follows in the case of the robots.txt (use CRXDE Light to create the node and it's properties):
jcr:primaryType = "sling:Mapping" (that's the type when you create a new node)
sling:internalRedirect = "/content/SITE/PATH/robots.html"
sling:match = "http/www.SITE.com/robots.txt"
Btw, this is the documentation for the mapping: http://sling.apache.org/site/mappings-for-resource-resolution.html
Hope that helps!
Europe, Middle East and Africa