[Bela1401]

Summary

This PR adds a practical monitoring guide for operators running a single Arc
execution layer + consensus layer on one Ubuntu host.

It documents:

• Prometheus scrape targets for EL and CL metrics
• a minimal Grafana + Prometheus setup
• dashboard provisioning
• local access via SSH tunneling
• common troubleshooting notes observed during real-world setup

Scope

This PR intentionally stays focused on a single-host operator setup and does not
attempt to cover multi-node or production observability architectures.

Related docs change

This PR also adds a reference from docs/running-an-arc-node.md to the new
docs/monitoring.md guide.

Notes

I kept the scope aligned with the feedback in the discussion:

• placement under docs/monitoring.md
• focused on one EL + one CL on one host
• reuses the existing monitoring dashboards already present in the repository

[Bela1401]

Opened this PR with the scope kept intentionally narrow: one execution layer + one consensus layer on one host, with Prometheus and Grafana for operator monitoring.

I also added the link from docs/running-an-arc-node.md to the new monitoring guide.

[Bela1401]

Validation screenshot from a live single-host setup is attached below.

[ZhiyuCircle]

Hi @Bela1401 ,

Apologies for the unexpected close. This PR was auto-closed as a side-effect of an update to the main branch in circlefin/arc-node. GitHub closes PRs when their base commit no longer exists on the target branch, which is why your contribution ended up here.

Your change is still very much welcome. To restore it, please rebase your branch onto the new main and open a fresh PR:

git fetch origin
git rebase origin/main
# resolve any conflicts if they come up
git push --force-with-lease

Then open a new PR against main — feel free to link back to this one for context, and we'll prioritize review. Thanks for contributing to Arc, and sorry for the inconvenience.