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/harness.ts

@@ -23,7 +23,7 @@ import { mustBeHandedOver, pinnedInto, referenceFor, repositoryOf, type HeldImag
 /**
  * The example bundle in mesh-host names a registry that no longer exists.
  *
- * `examples/foundation-first-node.lock` was written **for a target**, and the target was the lab: it
+ * `examples/foundation-first-node-nats.lock` was written **for a target**, and the target was the lab: it
  * pins `192.0.2.250:5000/…` because that is where the registry the lab used to raise served from.
  * That registry is gone, so those three references name nothing.
  *