DNS per zone metrics with DNSDist

[zachsmith1]

Context:
We're currently getting CRD metrics and LMDB zone/record replication metrics but we aren't getting user facing zone metrics.

Suggested Fix:
Implement functionality so that per zone DNS metrics are emitted to a centralized store. These should also be able to fetched by an export policy in datum projects.

[cc-datum]

I’ve been working on this. The PR with the work so far is here:
#6

Work Done

• Wired dnsdist to emit dnstap and exposed dnsdist metrics
• Enabled dns-collector telemetry with transformers, forwarding enriched JSON to Vector
• Added a Vector sidecar with log-to-metric pipelines for DNS metrics
• Added a monitoring stack (Prometheus, Loki, Grafana, dashboards) and a central Vector instance for remote write (for testing)
• Implemented zone → project enrichment (CSV builder and ConfigMap labels) to tag metrics with project metadata

Remaining / Follow-up Work

• Install and configure the central Vector instance in the infra repository for staging
• Update the domains and DNS enhancement documentation to reflect the changes made (https://github.com/datum-cloud/enhancements/tree/main/enhancements/domains-and-dns)
• Deploy the same setup to production edge clusters
• Revisit this pipeline using the OpenTelemetry Collector