Add VictoriaMetrics observability stack + sync catalog for monitoring test

- VM stack 10 charts: victoria-metrics-cluster/auth, victoria-logs-cluster,
  victoria-metrics-agent/alert, opentelemetry-collector, kube-state-metrics,
  prometheus-node-exporter, alertmanager, perses (JWT/OIDC, Infisical-ready)
- ArgoCD ApplicationSet (syncWave) + per-chart dip-values overlays
- doc/victoria-metrics-architecture.md, define-chart-resources updates
- includes pending working-tree changes (mlflow, kubeflow, apisix, CLAUDE.md)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

manifests/helm/alertmanager/1.37.0/Chart.yaml

@@ -0,0 +1,26 @@
+annotations:
+  artifacthub.io/license: Apache-2.0
+  artifacthub.io/links: |
+    - name: Chart Source
+      url: https://github.com/prometheus-community/helm-charts
+apiVersion: v2
+appVersion: v0.32.1
+description: The Alertmanager handles alerts sent by client applications such as the
+  Prometheus server.
+home: https://prometheus.io/
+icon: https://raw.githubusercontent.com/prometheus/prometheus.github.io/master/assets/prometheus_logo-cb55bb5c346.png
+keywords:
+- monitoring
+kubeVersion: '>=1.25.0-0'
+maintainers:
+- email: monotek23@gmail.com
+  name: monotek
+  url: https://github.com/monotek
+- email: naseem@transit.app
+  name: naseemkullah
+  url: https://github.com/naseemkullah
+name: alertmanager
+sources:
+- https://github.com/prometheus/alertmanager
+type: application
+version: 1.37.0