feat(infra): auto-discovered node metrics (CPU, RAM, Disk) and fully dynamic dashboard

- Add node-exporter container for host metrics (CPU, RAM, Disk)
- SVG gauge charts rendered server-side from Prometheus data
- Auto-detect compose project name from Docker labels
- Auto-detect web services via traefik.* labels for quick links
- Remove all hardcoded service name filters
- Dynamic system name based on compose project

infra/otel/prometheus.yml

@@ -10,3 +10,8 @@ scrape_configs:
       - targets: ['otel-collector:8889']
         labels:
           service: otel-collector
+
+  - job_name: 'node'
+    scrape_interval: 15s
+    static_configs:
+      - targets: ['node-exporter:9100']