## Summary
- Upgrade grafana-sidecar from 1.28.0 to 2.6.0 (the 2.x memory regression #462 is resolved; ~35MB static overhead is acceptable)
- Port build from Dockerfile to native Dagger container.py
- Add liveness/readiness probes using the new /healthz endpoint on port 8080
- Update docs to reflect container.py migration and remove stale pin note
## Test plan
- [ ] Build container: `mise run container-build-and-release grafana-sidecar`
- [ ] Update kustomization tag with new image tag
- [ ] Deploy from branch: `argocd app set grafana --revision grafana-sidecar-2.6.0 && argocd app sync grafana`
- [ ] Verify sidecar health endpoint: `kubectl exec -n monitoring <pod> -c grafana-sc-dashboard -- wget -qO- http://localhost:8080/healthz`
- [ ] Verify dashboards load in Grafana UI
- [ ] `mise run services-check`
Reviewed-on: #332
Every container now carries title, description, version, source, and
vendor labels per the OCI image spec. Version is derived from the
existing CONTAINER_APP_VERSION ARG at build time.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
