Register the prometheus appSpec entry

Points at the chart and values just added to devops-infra-helm-charts.
nameOverride pinned to "prometheus" so the Helm release name matches
what the chart's server Service naming depends on
("<release-name>-server") — see that repo's commit for the full
reasoning, since this file is the one place that decision has to be
made correctly for toolshed's already-seeded PROMETHEUS_URL to resolve.

Needs the usual two syncs to actually deploy: this values file only
takes effect once incubator-infra-k8s-admin-prd-ase1 is synced (which
creates/updates the child "prometheus" Application object), and that
child Application then needs its own sync to actually create anything
in the cluster.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Wajog7nELA3i8JWTjxYGHF

values/incubator-infra-k8s-admin-prd-ase1-values.yaml

@@ -132,3 +132,30 @@ appSpec:
     namespace: postgres
     chartDir: postgresql
     valuesDir: postgresql
+  - name: prometheus
+    # Server only — see custom-values.yaml for exactly why the chart's
+    # alertmanager/kube-state-metrics/node-exporter/pushgateway subcharts
+    # are all disabled, and why that is enough for what consumes this:
+    # toolshed's per-app CPU/memory metrics (docs/PRODUCT-ARCHITECTURE.md
+    # step 5), read straight from the built-in kubernetes-nodes-cadvisor
+    # scrape job.
+    #
+    # Vendored official chart (prometheus-community/prometheus), not
+    # hand-written — unlike postgresql, this one has a real official
+    # chart, and Contour/ArgoCD/Vault/Gitea/Harbor/Jenkins already use
+    # this same vendor-the-official-chart pattern rather than reinventing
+    # RBAC and Kubernetes service discovery by hand.
+    #
+    # nameOverride pinned to exactly "prometheus" for the same reason as
+    # postgresql/gitea above — without it every rendered object name
+    # becomes "prometheus-admin-prd-prd" instead. This one matters more
+    # than most: the chart's server Service renders as
+    # "<release-name>-server", so pinning the release name to "prometheus"
+    # is what makes it "prometheus-server" — the exact hostname toolshed's
+    # PROMETHEUS_URL already points at
+    # (prometheus-server.monitoring.svc.cluster.local), seeded before this
+    # existed so the connection would already be correct the day it did.
+    nameOverride: prometheus
+    namespace: monitoring
+    chartDir: prometheus
+    valuesDir: prometheus