HistorianBackendRegistryTests (#682) still expected the Gateway data source
to advertise the two AVEVA-native aggregates. Lane H2 (R08:2.1) refuses
them by default until historiangw#27, and the lane branch never updated
this Host test, so it failed after the rebase. The default case now expects
the ten raw-evaluated aggregates, and a new case pins that
ServerHistorian:Gateway:EnableNativeTimeWeighted=true, resolved through the
Host's registry, brings TimeAverage and Total back.
Claude-Session: https://claude.ai/code/session_01GT67AEHd2Acv1YPwGfXEoV
Joseph Doherty
4e76eeb57f