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/route-forwarding.test.ts

@@ -25,7 +25,7 @@
  * publicly-trusted certificate and answering an HTTP-01 challenge at the name — is proven separately
  * by certificates.test.ts, which drives the same proxy binary against a real ACME server (Pebble).
  *
- *   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-route-proxy-image.sh builds mesh-route-proxy:development into the local daemon;
  *   scenarios/route-forwarding.yml stocks it and alpine:latest, and serves both by digest.
  */