Internal documentation

Ops reference for on-call and deploy pipelines

# from CI
kubectl -n gzl-prod apply -f dist/
./scripts/wait-rollout.sh api-gateway webhook-worker

- metrics-ingest: known noisy during large backfills
- cert rotation: automated via cert-manager
- edge-cache: purge via /admin/cache/purge (VPN only)

primary: #ops-guzles (internal)
escalate: oncall@guzles.com