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]>

values.yaml

@@ -0,0 +1,34 @@
+## Default values for the apps-in-apps chart (App-of-Apps pattern).
+
+argocd:
+  # Namespace where ArgoCD (and thus the Application CRs) live.
+  namespace: argocd
+  # AppProject the generated Applications belong to.
+  project: default
+
+# List of child ArgoCD Applications this chart renders.
+# Each entry maps 1:1 to an `argoproj.io/v1alpha1 Application`.
+applications:
+  - name: valheim
+    enabled: true
+    source:
+      repoURL: https://git.smokyzone.de/SmokyZone/valheim-gitops.git
+      targetRevision: main
+      path: .
+      helm:
+        # Extra --set style values merged into the valheim-gitops chart.
+        # Keep secrets out of here - override via a sealed/external secret
+        # or ArgoCD parameter overrides instead.
+        parameters: []
+        # valueFiles:
+        #   - values.yaml
+    destination:
+      # Empty server means "the cluster ArgoCD itself runs in".
+      server: https://kubernetes.default.svc
+      namespace: valheim
+    syncPolicy:
+      automated:
+        prune: true
+        selfHeal: true
+      syncOptions:
+        - CreateNamespace=true