A comment claimed a test that does not exist

I wrote that a test asserts the control plane's placeholder expression
and the host's still agree. None does, and none in this repository could
— a unit test here can only assert what this repository already
believes.

That is precisely the thing this project refuses to tolerate: a stated
rule with no way to check it, which costs more than no rule because
people believe it. Written by me, today, in the same file that closes a
gap of the same kind.

What actually proves it is the lab, and the comment now says so.

internal/catalogue/secrets_into_files.go

@@ -24,9 +24,13 @@ import (
 
 // placeholder is what a module's file content says where a sealed value belongs: ${secret:name}.
 //
-// The same expression the host matches, written out again rather than shared. The two
-// repositories agree on a wire format, and a format read on both sides is exactly the thing that
-// must not be quietly changed on one of them; a test asserts they still agree.
+// The same expression the host matches, written out again rather than shared: they are separate
+// repositories and this is a wire format, like the shape of the declaration itself.
+//
+// **Nothing here can check that they agree, and the claim that something did was wrong.** A unit
+// test in this repository can only assert what this repository already believes. What proves it is
+// the lab, where a real host receives a real declaration and the file arrives filled — and where
+// the two expressions disagreeing shows up as a placeholder written through to a machine.
 var placeholder = regexp.MustCompile(`\$\{secret:([a-z0-9][a-z0-9-]*)\}`)
 
 // secretsUsed are the names a file's content asks for, in the order they first appear.