Add Pure FlashArray OpenMetrics exporter to monitoring namespace

- Deploy purestorage/pure-fa-om-exporter:v1.0.27 container
- Configure API token secret for utilidor FlashArray (jarvis user)
- Expose /metrics endpoint via ClusterIP service on port 9490
- ServiceMonitor for kube-prometheus-stack auto-discovery
- ArgoCD application for GitOps deployment (wave 3)
- Scrape interval: 60s (storage metrics low frequency)
- Resource limits: 200m CPU / 128Mi memory

Provides pure_* metrics namespace for FlashArray capacity, performance,
volume stats, host connectivity, etc.

cluster/platform/pure-exporter/application.yaml

@@ -0,0 +1,44 @@
+# ------------------------------------------------------------------------------
+# Platform: pure-exporter
+# Wave 3 — monitoring infrastructure, depends on kube-prometheus-stack
+# 
+# Pure Storage FlashArray OpenMetrics Exporter
+# Provides FlashArray telemetry (capacity, performance, volumes, hosts) to Prometheus
+# 
+# Installation flow:
+#   1. Secret with FlashArray API token created
+#   2. Deployment spins up exporter container
+#   3. Service exposes /metrics endpoint
+#   4. ServiceMonitor registers with Prometheus Operator
+#   5. Prometheus begins scraping pure_* metrics
+#
+# Prerequisites:
+#   - kube-prometheus-stack deployed in monitoring namespace (wave 2)
+#   - FlashArray API token for jarvis readonly user
+#   - Network connectivity to utilidor.local.mk-labs.cloud:443
+# ------------------------------------------------------------------------------
+apiVersion: argoproj.io/v1alpha1
+kind: Application
+metadata:
+  name: pure-exporter
+  namespace: argocd
+  annotations:
+    argocd.argoproj.io/sync-wave: "3"
+spec:
+  project: default
+  source:
+    repoURL: https://gitea.mk-labs.cloud/rblundon/homelab.git
+    targetRevision: main
+    path: cluster/platform/pure-exporter
+    directory:
+      exclude: "application.yaml"
+  destination:
+    server: https://kubernetes.default.svc
+    namespace: monitoring
+  syncPolicy:
+    automated:
+      prune: true
+      selfHeal: true
+    syncOptions:
+      - CreateNamespace=false  # monitoring namespace already exists
+      - ServerSideApply=true