Stop command only stops docker services

[canercidam]

For attached runs, we're cleaning up all host processes and custom services with lifecycle hooks after an interrupt. The equivalent of this should be the stop command for detached runs but it looks like that only takes down the docker services currently.

This issue currently causes leftovers from detached runs. Steps to reproduce:

• builder-playground start rbuilder/bin --detached
• builder-playground stop all
• Use e.g. htop to filter by rbuilder or reth which still appear as leftover processes

The right solution is probably interrupting the correct process like:

• Note down the PID to a pidfile under session dir, on every start
• Let the stop command discover the PID from that file and interrupt

(so that we get the same side effect as interrupting an attached run and have proper cleanup)