Add HistorianGrpcStoreForwardStatusProbe and the `grpc-sf-status-probe` CLI
command. The idle-baseline run against the live 2023 R2 server resolves the
plan's §9.3 handle question: the direct StorageService SF pull RPCs
(GetSFParameter / GetRemainingSnapshotsSize) require the OpenStorageConnection
console handle and are D2-gated (err 132, identical under read-only and
write-enabled sessions), while StatusService.GetHistorianConsoleStatus IS
reachable on the session string handle (=3 at idle).
Records the gRPC re-scope and the idle-baseline findings in
docs/plans/store-forward-cache-reverse-engineering.md §9. The probe writes
nothing and releases any console session immediately.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01B6mcaT2PjRFKcogzp9UkfC
Joseph Doherty
c2d8fb9bc8