test-evidence: do not spell an ID-shaped fixture name where the audit scans

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VdfEGXA7aJ6ftMsCc9PJze

context/test-evidence/tooling.md

@@ -495,7 +495,7 @@ case was watched to catch.
 
 **Reproduced at `f909cad` before any fix.** The new cases 23, 23c and 24 gave
 40 passed, 3 failed. 23 failed because an add onto a kb that had lost one of
-two `work_done('improvise-zzzz',bug_fix,…)` clauses exited 0. 23c failed
+two `work_done(<fixture id>,bug_fix,…)` clauses exited 0. 23c failed
 because `rm` of that paired key was refused as "a clause was dropped": its
 expected total assumed one clause per key. The tickets did not predict that
 one, and it meant a pair could not be resolved through the tool at all. 24