SPEC 2.4 named OtOpcUa and MxGateway as users; neither is (verified against every
app's default branch; MxGateway worker IPC is named pipes, OtOpcUa deliberately
does not gate readiness on gateway channels). Keep the check (removal is a breaking
API change; small, tested building block), mark it as no-current-consumers in SPEC
2.4/6/7, both READMEs, the shared-contract doc and GAPS.
Claude-Session: https://claude.ai/code/session_01GT67AEHd2Acv1YPwGfXEoV
Joseph Doherty
91fb2b48dd