Correct the anchor scar: no committed verdict was unearned

Soul checked the committed history. The script already threw on a missing
anchor, the affected mutation existed only in the working copy, and every
committed verdict was real. The rule stands, and gains the uniqueness check,
but the incident was narrower than first recorded.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

references/changelog.md

@@ -10,8 +10,15 @@ Record each change to the skill together with the evidence that motivated it.
   was to delete the unreachable rule too, not to write a test for state nothing
   can build.
 - **A mutation that never applied is not a passing mutation.** A multi-line
-  anchor matched nothing on a CRLF working tree, so one mutation never ran while
-  reporting success. Scripts must fail loudly on a stale anchor.
+  anchor matched nothing on a CRLF working tree. Scripts must fail loudly on a
+  stale anchor, and should also assert the anchor matches exactly once, since a
+  multi-site replace can read as "killed" when its test failed for another
+  reason.
+  - **Correction, same day.** Self first recorded this as "one mutation reported
+    a verdict it never earned". Soul checked the committed history: the script
+    already threw on a missing anchor, the affected mutation existed only in
+    Hands' working copy, and every committed verdict was real. The rule stands;
+    the incident was narrower than first written.
 
 ## 2026-09-16: an instance owns its mind, and a service owns the state