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.

internal/builder/standing_on_test.go

@@ -124,8 +124,7 @@ FROM golang:1.25-alpine AS go
 	if strings.Join(copies, "|") != "${MC_BASE} (a build argument the manifest does not declare)|vendor/tool:latest" {
 		t.Fatalf("copies out of undeclared images: %v", copies)
 	}
-	// A base fetched on its own is named apart: the mesh's own images still start FROM one, so
-	// it is said rather than refused until they declare theirs.
+	// A base fetched on its own is named apart, and refused like a copy (ADR 0097).
 	if strings.Join(bases, "|") != "golang:1.25-alpine" {
 		t.Fatalf("undeclared bases: %v", bases)
 	}