v0.5.0

Add a pre-run plan review and configurable docker network

Before writing files or running docker commands, setup now shows every
setting, file, and command it is about to run and asks for one go-ahead.
If the `web` network already exists with containers attached, the stack
can run on a separately named network instead: a generated compose
override remaps the external network and the traefik.docker.network
labels, so wsctl installs alongside an existing system untouched.