Move from docker compose run to a Python-managed container lifecycle.
Each project now gets a dedicated container that is started on demand
and stopped when opencode exits, instead of being recreated each time.
Use a shared home directory across projects so configurations presist.
The container are not destroyed, so tools and caches can be installed
specifically for a project by opencode itself once and reused, while
still avoiding long-running containers.
The problem was that we mounted `pwd` as HOME and that meant that
every time git was used it would look into the data and work for a
long time, and it would also commit everything there.
Now we have a central container-home directory in the directory
where we checked out this git repo and it is used by each session
independent of in which project directory we are.
It was impossible to have several arguments while calling
opencode in the container like `opencode auth list`, it would
just break. With this change this also works.
