refactor(ansible): rename freecad_mcp env vars and rework deployment

- Drop `FREECAD_MCP_` prefix from env vars (use `FREECAD_*`)
- Update freecad_mcp port from 22032 to 22061
- Document that FreeCAD bridge is required for tool calls
- Replace kottos deployment with pallas deployment

ansible/pplg/prometheus.yml.j2

@@ -68,6 +68,21 @@ scrape_configs:
         labels:
           component: web
 
+  # Athena — same shape as Mnemosyne: the Django container exposes /metrics
+  # (django-prometheus) proxied via nginx on the app port; a separate
+  # nginx-prometheus-exporter sidecar re-exposes the web container's
+  # stub_status in Prometheus format on the web-metrics port.
+  - job_name: 'athena'
+    metrics_path: '/metrics'
+    scrape_interval: 15s
+    static_configs:
+      - targets: ['{{ athena_app_metrics_host }}:{{ athena_app_metrics_port }}']
+        labels:
+          component: app
+      - targets: ['{{ athena_web_metrics_host }}:{{ athena_web_metrics_port }}']
+        labels:
+          component: web
+
   # Pallas — each deployment is one scrape target (registry port).
   # Pallas uses a single process-global registry, so per-agent /metrics
   # endpoints serve the same snapshot; the `agent` dimension is carried