Generate Argo CD Applications dynamically with an ApplicationSet Git directory generator

Steps

1. Install the ApplicationSet controller (bundled with Argo CD v2.3+; verify with `kubectl get deploy -n argocd argocd-applicationset-controller`)
2. Author an ApplicationSet manifest using the `git` generator with `directories` pointing to a path glob in your config repo (e.g., `apps/*`)
3. Define the Application template inside the ApplicationSet spec; use `{{path.basename}}` to parameterize the Application name and target namespace per discovered directory
4. Add the ApplicationSet to the cluster with `kubectl apply -f applicationset.yaml`; Argo CD creates one Application per matched directory
5. Push a new directory to the config repo to automatically provision a new Application; remove the directory to trigger deletion (if configured)
6. Use `argocd appset list` and `argocd appset get <name>` to inspect generator output and debug template rendering