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/tools-confluence.yml

@@ -11,7 +11,7 @@
 #
 #   MESH_LAB_HOST_BINARY=.../mesh-host   MESH_LAB_BUNDLE=.../examples/substrate-first-node.lock
 #   scripts/build-module-runtime.sh confluence builds mesh-runtime-confluence:development into the
-#   local daemon, which this scenario stocks and serves by digest from its own registry. confluence
+#   local daemon, which the machine pulls from the internet over its uplink. confluence
 #   needs no service image — it is tools-only.
 scenario: tools-confluence
 
@@ -23,17 +23,15 @@ segments:
 machines:
   anchor:
     at: { segment: hosting, address: [192.0.2.10] }
+    egress: true
     inbound: allow
     memory: 3GiB
     cpus: 2
 
 images:
-  # The first-node substrate: store, broker, control.
-  - postgres:17-alpine
-  - cloudamqp/lavinmq:latest
   - mesh-control:development
   # confluence's runtime, built by scripts/build-module-runtime.sh confluence into the local daemon
-  # and stocked into the scenario's own registry, which is where the host pulls it from. There is no
+  # and loaded onto the machine, which holds it by its own image ID. There is no
   # service image: confluence is tools-only and outbound-only.
   - mesh-runtime-confluence:development