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/base/vm-system/kustomization.yaml

@@ -0,0 +1,6 @@
+---
+apiVersion: kustomize.config.k8s.io/v1beta1
+kind: Kustomization
+
+resources:
+  - namespace.yaml

apps/base/vm-system/namespace.yaml

@@ -0,0 +1,7 @@
+---
+apiVersion: v1
+kind: Namespace
+metadata:
+  labels:
+    app.kubernetes.io/name: vm-system
+  name: vm-system