nodes.md, nightly-rotation.md: scratch guest 9202 takes its address by DHCP (.114 until 2026-10-19, now .121); read it from the guest

documentation/runbooks/nightly-rotation.md

@@ -26,7 +26,8 @@ baked on a Saturday night, ahead of the Sunday). A Sunday with no bake is what `
 
 **The nine standing apps of demo-hp come first.** They cannot be a throwaway on guest 9201 (same stack
 name), so they are walked on the **scratch guest 9202** (R-481, built 2026-09-13: under the demo-hp
-customer, hub off, tunnel off, `https://192.168.0.114` with the same Host names and password).
+customer, hub off, tunnel off, its DHCP address with the same Host names and password — `.121` since 2026-10-19; read it with
+`ssh hp pct exec 9202 -- ip -4 -o addr show eth0`).
 
 ## Standing on demo-hp — walked on the scratch guest 9202