A bed says what it actually needs to be pointed at

The instructions in every bed named the bundle that raises the predecessor's
broker, so a first attempt ends in a control plane crash-looping on a missing
MESH_BUS_NATS — which reads like a broken lab. They name the bundle that works
now, and the README says the host binary needs SYSTEM=arch, because one built
without it refuses everything with an empty system name.

And the three habits that each cost a run before they were adopted:
MESH_LAB_KEEP to leave the machine standing, MESH_LAB_WARM while iterating,
and rebuilding all three repositories the bed places rather than the one that
changed.

test/integration/assigned-catalogue-media.test.ts

@@ -23,7 +23,7 @@
  *
  * All is assigned to the one anchor, pushed ONCE, and the node converges ONCE with both modules up.
  *
- *   MESH_LAB_HOST_BINARY=.../mesh-host   MESH_LAB_BUNDLE=.../examples/foundation-first-node.lock
+ *   MESH_LAB_HOST_BINARY=.../mesh-host   MESH_LAB_BUNDLE=.../examples/foundation-first-node-nats.lock
  *   scripts/build-module-runtime.sh {sonarr,radarr} build the runtime images into the local daemon;
  *   scenarios/catalogue-media.yml stocks them. lscr.io/linuxserver/{sonarr,radarr} must be in the
  *   local daemon; the service images are pulled from the internet. Each *arr runtime is given a lab