Context

The rust protocol team is using sysgo to hold long-running, in memory, instances of op-stack devnets for quick feature iteration and network health monitoring.

We would like to add observability into our devnets - for instance, collect metrics emitted by CL/EL into grafana dashboards. There are several ways to do that:

• Since the devnets are spawn using random OS ports - we'll need to parse the ports each node has bound to and forward the metrics port to a grafana instance.
• We could also provide a port mapping as an input of sysgo, a bit like in the syext mode. This would allow us to run sysgo's devnet in a docker container (no port conflicts), and deterministically map the ports to a grafana instance.