I wrote a simple compiler for sencha touch files in node.js and uglify. It basically takes all your project files and the Sencha touch library and wraps it into one minified .js file. This is something I struggled with and was not sure how to do with the Sencha SDK tools so I just wrote my own.
You can find it here:
It is pretty basic. It reads all your files and parses out the requires, extends, and defines using regex. Once it builds an object list based on that it uses topological sorting to put all the files in the right order. Then it joins it all and spits out one file with your app in it. I have tested it on my own touch app and everything works pretty well.