feat: migrate vm-system to ArgoCD (#80)

Migrate Victoria Metrics operator from Terragrunt to ArgoCD/Kustomize.
Deploys victoria-metrics-operator v0.57.1 with 2 replicas in vm-system.

💘 Generated with Crush

Assisted-by: Claude Sonnet 4.6 via Crush <crush@charm.land>

Reviewed-on: #80

apps/overlays/au-syd1/vm-system/kustomization.yaml

@@ -0,0 +1,16 @@
+---
+apiVersion: kustomize.config.k8s.io/v1beta1
+kind: Kustomization
+
+namespace: vm-system
+
+resources:
+  - ../../../base/vm-system
+
+helmCharts:
+  - name: victoria-metrics-operator
+    repo: https://victoriametrics.github.io/helm-charts/
+    version: "0.57.1"
+    releaseName: victoria-metrics-operator
+    namespace: vm-system
+    valuesFile: values.yaml

apps/overlays/au-syd1/vm-system/values.yaml

@@ -0,0 +1,9 @@
+logLevel: "info"
+replicaCount: 2
+resources:
+  limits:
+    cpu: 500m
+    memory: 512Mi
+  requests:
+    cpu: 50m
+    memory: 128Mi