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/first-node.yml

@@ -1,8 +1,8 @@
 # One machine, raising a substrate from the bundle its host carries.
 #
 # This is the bootstrap class (novox/hq ADR 0009): no forge, no control plane to talk to, no
-# delivery. It exists to develop the steps of raising a mesh on a machine with no route out —
-# a container runtime, a store, the control plane's schema in it, and the broker.
+# delivery. It exists to develop the steps of raising a mesh on a machine that has nothing but a
+# connection — a container runtime, a store, the control plane's schema in it, and the broker.
 #
 # It stops before the control plane *runs*, because there is nothing for it to serve yet.
 scenario: first-node
@@ -15,14 +15,15 @@ segments:
 machines:
   anchor:
     at: { segment: hosting, address: [192.0.2.10] }
+    egress: true
     inbound: allow
 
-# Placed into a registry the scenario raises, which is what a real node pulls from anyway. The
-# digests below are the ones that registry assigns, and that satisfies pinning: what is required
-# is a reference that is exact and cannot move (novox/hq ADR 0006).
+# The control plane's own image exists in no registry — it is built from source, and until this
+# mesh has a registry of its own there is nowhere to have pushed it. So it is loaded onto the
+# machine and named by the digest of its own configuration, which is exact and cannot move, which
+# is what pinning asks for (novox/hq ADR 0006). The store and the broker are ordinary third-party
+# images, and the machine pulls them from the internet like anything else.
 images:
-  - postgres:17-alpine
-  - cloudamqp/lavinmq:latest
   - mesh-control:development
 
 place: