Replace the prometheus appSpec entry with victoria-metrics-single/vmagent/node-exporter

Matches the chart-side replacement in devops-infra-helm-charts. Three
Applications now where there was one, since victoria-metrics-single
bundles no scraper or exporter the way the Prometheus chart did.

Sync order matters here specifically: victoria-metrics-single needs to
exist before vmagent's remote_write target resolves, though ArgoCD sync
failures are naturally retried so this only affects how quickly it
converges, not whether it does.

Verified with `helm template` against generic-argo-apps-chart and this
values file: 11 Applications render, the three new ones present and
correctly formed, nothing left pointing at the removed prometheus
chartDir.

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

@@ -132,30 +132,48 @@ 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.
+  - name: victoria-metrics-single
+    # Replaces the Prometheus server this entry briefly was (see git
+    # history on this file) — same job, lower RAM/disk footprint for the
+    # same metric volume, and it speaks Prometheus's own query API
+    # (/api/v1/query) so nothing downstream (toolshed's metrics
+    # connection, docs/PRODUCT-ARCHITECTURE.md step 5) needed to change,
+    # only the URL it points at.
     #
-    # 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.
+    # Vendored official chart (victoriametrics/helm-charts), same
+    # vendor-the-official-chart pattern as Contour/ArgoCD/Vault/Gitea/
+    # Harbor/Jenkins. This exact directory name already existed in this
+    # repo before — a leftover GKE-targeted vendored copy from the
+    # original Meesho monorepo import — and was removed rather than
+    # adapted; see that chart's own Chart.yaml comment.
     #
-    # 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
+    # nameOverride pinned to exactly "victoria-metrics-single" for the
+    # same reason as postgresql/gitea/prometheus above: the chart's
+    # server Service renders as "<release-name>-server", so this is what
+    # makes it resolvable at a predictable hostname
+    # (victoria-metrics-single-server.monitoring.svc.cluster.local:8428)
+    # rather than "victoria-metrics-single-admin-prd-prd-server".
+    nameOverride: victoria-metrics-single
     namespace: monitoring
-    chartDir: prometheus
-    valuesDir: prometheus
+    chartDir: victoria-metrics-single
+    valuesDir: victoria-metrics-single
+  - name: vmagent
+    # The scraper — pulls from the same targets the Prometheus server
+    # used to scrape directly (kubelet's cAdvisor endpoint, and anything
+    # carrying a prometheus.io/scrape annotation, e.g. node-exporter
+    # below) and remote_writes into victoria-metrics-single. Needs that
+    # component's Service name, so bring it up after, not before.
+    nameOverride: vmagent
+    namespace: monitoring
+    chartDir: vmagent
+    valuesDir: vmagent
+  - name: node-exporter
+    # Host-level metrics (disk/memory/load) — independent of which TSDB
+    # stores them, so vendored standalone rather than as a subchart of
+    # anything. Was a subchart of the (now removed) Prometheus server
+    # entry; moved out to its own release when that server was replaced,
+    # since victoria-metrics-single has no equivalent bundled subchart.
+    nameOverride: node-exporter
+    namespace: monitoring
+    chartDir: node-exporter
+    valuesDir: node-exporter