Updates for grafana stack

inventory/host_vars/ai-server-4080.yml

@@ -8,6 +8,9 @@ ansible_control_node: true
 ansible_connection: local
 act_runner_enabled: true
 
+# Central Loki + Prometheus + Grafana (roles/observability).
+observability_stack: true
+
 # This host's pre-existing ~/.ssh/id_ed25519 is a personal key WITH a passphrase,
 # which hangs the (non-BatchMode) gitea access probe. Use a dedicated,
 # passphrase-less deploy key here instead.