Also updates the now-obsolete CompileAndRegister_NonCompilingUpdate test
(InboundScriptExecutorTests.cs, not in the plan's Files list) to assert the
deliberate DB-authoritative behavior: a broken save now 500s consistently on
every node instead of the stale delegate silently serving.
Claude-Session: https://claude.ai/code/session_01MtdgwpEeCUn6cUA5f1LMPj
Joseph Doherty