Enable Argo CD self-management via dedicated Application

Create app-argocd Application to manage argocd resources using kustomize.
Update stack Application exclusion to allow Application manifests while
excluding direct resource management (prevents namespace errors from
directory recursion bypassing kustomization).

Architecture:
- stack Application manages Application manifests (app-*.yaml)
- argocd Application manages argocd resources via kustomize
- Both Applications can self-manage through this pattern

Co-Authored-By: Paperclip <noreply@paperclip.ing>

apps/app-argocd.yaml

@@ -0,0 +1,20 @@
+apiVersion: argoproj.io/v1alpha1
+kind: Application
+metadata:
+  name: argocd
+  namespace: argocd
+spec:
+  project: default
+  source:
+    repoURL: git@forgejo.forgejo.svc.cluster.local:basicstack/stack.basicstack.de.git
+    targetRevision: main
+    path: apps/argocd
+  destination:
+    server: https://kubernetes.default.svc
+    namespace: argocd
+  syncPolicy:
+    automated:
+      prune: false  # Manual approval for deletions
+      selfHeal: true
+    syncOptions:
+    - CreateNamespace=true

apps/argocd/app-stack-basicstack-de.yaml

@@ -11,6 +11,9 @@ spec:
     path: apps
     directory:
       recurse: true
+      exclude: |
+        argocd/*
+        !argocd/app-*.yaml
   destination:
     server: https://kubernetes.default.svc
   syncPolicy:

apps/argocd/argocd-install.yaml

@@ -31221,8 +31221,6 @@ kind: ConfigMap
 metadata:
   labels:
     app.kubernetes.io/name: argocd-cm
-  annotations:
-    test.self-management: "enabled"
 data:
   url: https://argo.basicstack.de
   oidc.config: |