Adds the positive control that the prior C2 evidence lacked. The SAME native WCF
event-read client returns real events (5) from a local AVEVA Historian 2020 but 0
from the 2023 R2 server over the identical sequence and window, while both boxes
hold tens of thousands of events in SQL — isolating the zero-rows to the 2023 R2
server, not the client, protocol, or serializers.
- wcf-event-read-spike-results.md: new "2026-06-26 positive control" section
(2020 vs 2023 R2 A/B from one WCF client; stock-2020-client version-self-block
caveat; stock-2023R2 gRPC cross-check).
- grpc-event-query-capture.md: re-control note — the 2026-06-22 stock 50-row
capture did NOT reproduce; the stock 2023 R2 client now also returns 0 rows.
- HistorianGrpcIntegrationTests: correct the stale "capture-gated, NOT
server-gated" comment to the server-gate conclusion backed by the controls.
Sanitized throughout (counts, native return codes, buffer lengths only).
Claude-Session: https://claude.ai/code/session_012SDSQ3AcaXqPcBtDESBRii
Joseph Doherty