It says in that error log
Package python-image (2.7.3-r0.3) installed in root is up to date.
Unknown package 'nano'.
Package libe2p2 (1.42.9-r0) installed in root is up to date.
which, coupled with the information about nano package not being there makes me think the nano recipe must be the reason. So please post it and let's see.
Your layer.conf and the directory stucture looks ok, so I don't think it has any relation to the problem.