The control plane's recipe starts FROM the base its manifest declares, and an undeclared base is refused

The mesh's own images declare theirs now, so the refusal ADR 0097 deferred is live.
The builder's own image and the examples take arguments with defaults; make builds
them, not the mesh.

module.json

@@ -66,6 +66,12 @@
         "kind": "image",
         "from": "Dockerfile"
       }
+    ],
+    "on": [
+      {
+        "arg": "GO_BASE",
+        "image": "golang@sha256:1ae0735f00daffa3aaf1363a5184c0d2dc55c78e3db4ec70241cdac97bf84b59"
+      }
     ]
   }
 }