Copilot instructions

# Copilot instructions

Read `AGENTS.md` in the repository root first. It is the project guide, and everything below is only the short version for when you have not opened it.

- This exporter's metric names and labels are a public contract. Renaming or relabeling an established series silently breaks users' dashboards and alerts, so treat existing names as frozen.
- The expected `.metrics` files under `internal/integration/testdata/` are generated, not hand-edited. Regenerate them with the integration suite's `-update` flag and review the diff.
- The Helm chart's `README.md` is generated and must never be edited directly: its prose lives in `README.md.gotmpl`, and its values reference comes from the comments in `values.yaml`. Regenerate with helm-docs after changing either. A new key in `values.yaml` also needs an entry in `values.schema.json`, which rejects unknown keys.
- The Grafana dashboards under `docs/grafana/` are the source of truth; the copies shipped in the chart must stay byte-identical, and CI enforces it. See `docs/grafana/README.md` for the query conventions, several of which fail silently when violated.
- Verify with `go test ./...` and the `task lint:*` target relevant to what you changed; CI runs the full `task lint` set.
- Commits follow the conventional-commit format (`type(scope): imperative description`) with a body explaining what changed and why, and carry a DCO sign-off. Do not add AI attribution of any kind, such as "generated with" lines or AI co-author trailers.