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/victoria-logs-cluster/0.1.5/templates/pdb.yaml

@@ -0,0 +1,29 @@
+{{- $ctx := dict "helm" . }}
+{{- range $name, $app := .Values }}
+{{- if and (kindIs "map" $app) $app.enabled ($app.podDisruptionBudget).enabled }}
+{{- $pdb := $app.podDisruptionBudget }}
+{{- $_ := set $ctx "extraLabels" $pdb.labels }}
+{{- $_ := set $ctx "appKey" $name }}
+{{- $fullname := include "vm.plain.fullname" $ctx }}
+---
+apiVersion: policy/v1
+kind: PodDisruptionBudget
+metadata:
+  name: {{ $fullname }}
+  namespace: {{ include "vm.namespace" $ }}
+  labels: {{ include "vm.labels" $ctx | nindent 4 }}
+  {{- $_ := unset $ctx "extraLabels" }}
+spec:
+  {{- with $pdb.minAvailable }}
+  minAvailable: {{ . }}
+  {{- end }}
+  {{- with $pdb.maxUnavailable }}
+  maxUnavailable: {{ . }}
+  {{- end }}
+  {{- with $pdb.unhealthyPodEvictionPolicy }}
+  unhealthyPodEvictionPolicy: {{ . }}
+  {{- end }}
+  selector:
+    matchLabels: {{ include "vm.selectorLabels" $ctx | nindent 6 }}
+{{- end }}
+{{- end }}