fix(argocd): add argocd-rbac-cm granting platform-engineer read+sync on applications

The platform-engineer ArgoCD local account had apiKey+login capabilities
but no RBAC role assignment. With no argocd-rbac-cm ConfigMap in the repo,
the default policy gave the account zero permissions, so every API call
to list applications returned an empty list — the watchdog could not see
any apps to check their health.

This adds an argocd-rbac-cm ConfigMap with a role:platform-engineer that
has get (read) and sync on all applications in all projects, and assigns
the platform-engineer account to that role.

argocd/argocd-rbac-cm.yaml

@@ -0,0 +1,15 @@
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: argocd-rbac-cm
+  namespace: argocd
+  labels:
+    app.kubernetes.io/name: argocd-rbac-cm
+    app.kubernetes.io/part-of: argocd
+data:
+  policy.csv: |
+    # Grant the platform-engineer local account read + sync access to all applications
+    p, role:platform-engineer, applications, get, */*, allow
+    p, role:platform-engineer, application, sync, */*, allow
+    g, platform-engineer, role:platform-engineer
+  policy.default: ""