feat(ansible): idempotent role-based host config for both production VMs

common/firewall/docker-tls/platform/lab-host/monitoring-agent/backup roles,
orchestrated by site.yml with the ordering that matters (firewall/TLS land
before the services that depend on them). Ansible Vault for secrets, no new
tool introduced for this project's modest secret surface. Explicit
dev/staging/production environment separation, no secrets committed
(.gitignore covers vault plaintext, TLS keys, Terraform state, *.env).

Validated: ansible-playbook --syntax-check clean.

infra/environments/production/provisioner-config/lab-hosts.yaml

@@ -0,0 +1,16 @@
+# Production lab_hosts seed — points at the real rn-lab-host-01 VM instead of Phase 1's dev
+# Unix socket. Same mechanism the Provisioner has had since Phase 1
+# (platform/provisioner/config/lab-hosts.seed.yaml), just pointed at a real remote endpoint —
+# no application code changes required for this, see docs/PRODUCTION_NETWORK_SECURITY.md §7.
+#
+# {{ lab_host_ip }} is an Ansible template variable — see infra/ansible/group_vars/production.yml.
+# Rendered by the `platform` role; the raw file here keeps the placeholder for readability.
+
+lab_hosts:
+  - lab_host_id: labhost-01
+    display_name: "RootNode Lab Host VM 01 (production)"
+    endpoint: "tcp://{{ lab_host_ip }}:2376"
+    tls_ca_path: /etc/rootnode/docker-tls/ca.pem
+    tls_cert_path: /etc/rootnode/docker-tls/provisioner-client-cert.pem
+    tls_key_path: /etc/rootnode/docker-tls/provisioner-client-key.pem
+    enabled: true