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/opentelemetry-collector/0.156.2/templates/pdb.yaml

@@ -0,0 +1,19 @@
+{{- if and .Values.podDisruptionBudget.enabled (or (eq .Values.mode "deployment") (eq .Values.mode "statefulset")) }}
+apiVersion: {{ include "podDisruptionBudget.apiVersion" . }}
+kind: PodDisruptionBudget
+metadata:
+  name: {{ include "opentelemetry-collector.fullname" . }}
+  namespace: {{ template "opentelemetry-collector.namespace" . }}
+  labels:
+    {{- include "opentelemetry-collector.labels" . | nindent 4 }}
+spec:
+  {{- if .Values.podDisruptionBudget.minAvailable }}
+  minAvailable: {{ .Values.podDisruptionBudget.minAvailable }}
+  {{- end  }}
+  {{- if .Values.podDisruptionBudget.maxUnavailable }}
+  maxUnavailable: {{ .Values.podDisruptionBudget.maxUnavailable }}
+  {{- end  }}
+  selector:
+    matchLabels:
+      {{- include "opentelemetry-collector.selectorLabels" . | nindent 6 }}
+{{- end }}