Fix Caddy ingress ACME email and RBAC issues

- Add acme_email_key constant for spec.yml parsing
- Add get_acme_email() method to Spec class
- Modify install_ingress_for_kind() to patch ConfigMap with email
- Pass acme-email from spec to ingress installation
- Add 'delete' verb to leases RBAC for certificate lock cleanup

The acme-email field in spec.yml was previously ignored, causing
Let's Encrypt to fail with "unable to parse email address".
The missing delete permission on leases caused lock cleanup failures.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

stack_orchestrator/data/k8s/components/ingress/ingress-caddy-kind-deploy.yaml

@@ -93,6 +93,7 @@ rules:
       - get
       - create
       - update
+      - delete
 ---
 apiVersion: rbac.authorization.k8s.io/v1
 kind: ClusterRoleBinding