Rename mesh-control -> mesh-controller, substrate -> foundation

One name per thing, per the HQ glossary: the module/container/image/binary/repo
becomes mesh-controller, the seat the-controller, and the store+broker pair the
foundation (embedded base bundles, default template and example lock renamed with
their go:embed directives). No behaviour change — a pure vocabulary rename.

Claude-Session: https://claude.ai/code/session_01D6qtiYU3P9jk3pnAXyAFyx

scenarios/openai-bed.yml

@@ -11,7 +11,7 @@
 #   OPENAI_API_KEY (env file + the Codex auth.json). The test asserts the written key equals the one
 #   the operator set — through the sealed delivery path, unchanged.
 #
-#   MESH_LAB_HOST_BINARY=.../mesh-host   MESH_LAB_BUNDLE=.../examples/substrate-first-node.lock
+#   MESH_LAB_HOST_BINARY=.../mesh-host   MESH_LAB_BUNDLE=.../examples/foundation-first-node.lock
 #   Build the consumer runtime image into the local daemon first (raise() stocks it from there):
 #     scripts/build-module-runtime.sh openai-consumer  /tmp/openai-consumer.tar
 scenario: openai-bed
@@ -30,7 +30,7 @@ machines:
     cpus: 2
 
 images:
-  - mesh-control:development
+  - mesh-controller:development
   # The static-key consumer runtime, built by scripts/build-module-runtime.sh into the local daemon and
   # loaded onto the machine, which holds it by its own image ID.
   - mesh-runtime-openai-consumer:development