Scenarios: egress where images are needed, and images: cut to what is ours

Every scenario that places a container runtime gives each of its machines
`egress: true` — a node that runs modules pulls images from the internet, which is what
a node does. The underlay-only scenarios (bootstrap-single, behind-nat,
segmented-and-unforwardable, the-ordinary-shape, two-on-a-segment) stay sealed on
purpose: an extra NIC would change the very reachability they are asserting about.

`images:` keeps only the mesh's own — 55 third-party entries leave whole-mesh-full
alone, and the machine fetches them itself by the digest its module.json already pins.
The whole-mesh beds also say per machine which of ours they get: novox the substrate
control plane and its own fifteen runtimes, ace its twenty-four, the two workstations
one each. That is not a lab economy. An operator's workstation holds the images its own
modules need, and giving these two the union would put some thirty gigabytes onto a
thirty-gigabyte disk.

bootstrap-with-registry.yml is deleted. It existed only to demonstrate the lab's
registry, nothing referenced it, and there is nothing left for it to demonstrate.

Claude-Session: https://claude.ai/code/session_01LrgweAeERJYBg88c5cKDzF

scenarios/catalogue-small.yml

@@ -13,7 +13,7 @@
 #   MESH_LAB_HOST_BINARY=.../mesh-host   MESH_LAB_BUNDLE=.../examples/substrate-first-node.lock
 #   scripts/build-module-runtime.sh {postgres,redis,minio,plex} build the four runtime images into the
 #   local daemon (postgres carries psql, minio carries mc), which this scenario stocks and serves by
-#   digest from its own registry. The service images must be in the local daemon to be stocked.
+#   the internet over its uplink. Only the mesh's own images come from the local daemon.
 scenario: catalogue-small
 
 segments:
@@ -24,6 +24,7 @@ segments:
 machines:
   anchor:
     at: { segment: hosting, address: [192.0.2.10] }
+    egress: true
     inbound: allow
     # Sized up: this anchor runs the substrate (store, broker, control) plus four modules — three of
     # which are a server container and a runtime container each — so a dozen containers at once. The
@@ -32,13 +33,7 @@ machines:
     cpus: 4
 
 images:
-  # The first-node substrate: store, broker, control.
-  - postgres:17-alpine
-  - cloudamqp/lavinmq:latest
   - mesh-control:development
-  # The module server images.
-  - redis:7-alpine
-  - minio/minio:latest
   # The four per-module runtimes, built by scripts/build-module-runtime.sh and stocked here. plex
   # needs no server image in the lab — its runtime serves tools with no Plex to reach.
   - mesh-runtime-postgres:development