Add app-of-apps Helm chart for ArgoCD

Renders ArgoCD Applications from values.yaml, including one for the
valheim-gitops chart. Includes a one-time bootstrap manifest to
register this chart itself as an ArgoCD Application.

Co-authored-by: Copilot <[email protected]>

bootstrap/root-application.yaml

@@ -0,0 +1,27 @@
+# One-time bootstrap manifest.
+#
+# Apply this manually once (kubectl apply -f bootstrap/root-application.yaml)
+# so ArgoCD manages itself as a Helm-based Application. From then on, any
+# entry added to values.yaml -> applications[] is rolled out automatically.
+apiVersion: argoproj.io/v1alpha1
+kind: Application
+metadata:
+  name: apps-in-apps
+  namespace: argocd
+  finalizers:
+    - resources-finalizer.argocd.argoproj.io
+spec:
+  project: default
+  source:
+    repoURL: https://git.smokyzone.de/SmokyZone/apps-in-apps.git
+    targetRevision: main
+    path: .
+  destination:
+    server: https://kubernetes.default.svc
+    namespace: argocd
+  syncPolicy:
+    automated:
+      prune: true
+      selfHeal: true
+    syncOptions:
+      - CreateNamespace=true