metrics: phase 3 straylight/rift scrapes and hyperborea units

Review, no switch. node-laptop for talos/titan is excluded from
FleetTargetDown. llama-straylight scrape uses params.model for
ornith-1.5-35b-a3b (router 400 without it; will load if cold).

configs/metrics/hyperborea/override.conf

@@ -0,0 +1,7 @@
+# /etc/systemd/system/prometheus-node-exporter.service.d/override.conf
+[Unit]
+After=tailscaled.service
+Wants=tailscaled.service
+
+[Service]
+Restart=on-failure

configs/metrics/hyperborea/prometheus-node-exporter

@@ -0,0 +1,3 @@
+# /etc/default/prometheus-node-exporter on hyperborea (Debian).
+# Bind the tailscale IP only. LAN 192.168.88.154:9100 must stay closed.
+ARGS="--web.listen-address=100.112.40.10:9100"