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

test/integration/objectstore.test.ts

@@ -33,7 +33,7 @@ const skip = !capability.usable
   ? `lab not usable: ${capability.why}`
   : !provisioner
     ? "set MESH_LAB_OBJECTSTORE_PROVISIONER to a built provisioner " +
-      "(mesh-control: go build ./examples/objectstore-provisioner)"
+      "(mesh-controller: go build ./examples/objectstore-provisioner)"
     : false;
 
 const SCENARIO = "an-object-store";