R0.6: fail-closed server interface-version gate at connect

Turns the previously-discarded GetInterfaceVersion result into a connect-time
version pin. The native buffers carried in the WCF/MDAS body (and in the 2023 R2
gRPC bytes fields) are framed per native interface version; parsing them against
an unexpected version risks silent misinterpretation, so we throw rather than
best-effort parse.

- HistorianServerVersionGate + HistorianServiceInterface: evidence-based
  supported versions discovered from a live Historian 2020 server (product
  20.0.000) via the wcf-probe command — History=11, Retrieval=4, Transaction=2.
  Status' GetInterfaceVersion returns 0, so Status is reachability-only.
- HistorianClientOptions.VerifyServerInterfaceVersion (default true) — bypass
  knob for bringing up a server whose reported integers aren't yet captured
  (e.g. a 2023 R2 gRPC endpoint carrying the same proven 2020 buffers).
- Wired into both transports' connect paths: WCF history (auth-chain helper) +
  retrieval (read orchestrator), and gRPC history + retrieval.
- Mismatch throws ProtocolEvidenceMissingException naming reported/expected
  version and the bypass knob.

10 new unit tests (198 total green). Verified the gate does not regress the
proven WCF read path: a live read against the local 2020 server reaches past the
gate (Retr=4 matches) — the only live failures are a pre-existing environmental
read timeout (OperationCanceledException), identical with and without this change.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/AVEVA.Historian.Client/HistorianClientOptions.cs

@@ -62,4 +62,16 @@ public sealed class HistorianClientOptions
     /// true the server certificate chain is not validated. Default false.
     /// </summary>
     public bool GrpcUseTls { get; init; }
+
+    /// <summary>
+    /// When true (default) the SDK verifies, at connect time, that the Historian server
+    /// reports the native interface versions its byte serializers were built against
+    /// (History=11, Retrieval=4, Transaction=2 — evidence from a live AVEVA Historian 2020
+    /// server). A mismatch throws <see cref="ProtocolEvidenceMissingException"/> rather than
+    /// risk misparsing version-framed native buffers. Set false only when you have
+    /// independently confirmed wire compatibility with a different server version — e.g.
+    /// when bringing up a 2023 R2 gRPC server whose reported interface integers have not yet
+    /// been captured. See <see cref="HistorianServerVersionGate"/>.
+    /// </summary>
+    public bool VerifyServerInterfaceVersion { get; init; } = true;
 }