Wire SDK for remote-TCP end to end; live-verify RemoteTcpIntegrated

Executes docs/plans/tcp-connection-validation.md. Full read-only SDK
surface now works against a remote AVEVA Historian over Net.TCP with
Windows transport authentication. 124/124 tests pass; the +10 new live
integration tests in RemoteTcpIntegrationTests.cs are gated by
HISTORIAN_REMOTE_TCP_HOST + HISTORIAN_REMOTE_TCP_TAG.

Two SDK bugs found while executing the plan:

1. Historian2020ProtocolDialect.ReadRawAsync / ReadAggregateAsync /
   ReadAtTimeAsync / ReadEventsAsync had explicit
   `if (_options.Transport != HistorianTransport.LocalPipe) return Missing<T>`
   guards. These were a guardrail from before the orchestrators handled
   TCP; the orchestrators have always used CreateBindingPair(options)
   which dispatches on transport correctly. Gates removed.

2. HistorianWcfStatusClient and HistorianWcfEventOrchestrator hardcoded
   HistorianWcfBindingFactory.CreatePipeEndpointAddress for the auxiliary
   services (Stat, Trx, Retr). Worked for LocalPipe; for TCP it produced
   an EndpointAddress with scheme net.pipe attached to a TCP binding
   (channel factory rejected the URI). Worse, when only the endpoint was
   transport-aware, the binding still requested a Windows-transport-
   security upgrade that the Stat endpoint over TCP doesn't support
   (auxiliaries don't repeat the auth — the Hist session is already
   authenticated). Added two helpers:
   - HistorianWcfBindingFactory.CreateAuxiliaryEndpointAddress(options, name)
     -> net.pipe for LocalPipe, net.tcp for remote
   - HistorianWcfBindingFactory.CreateAuxiliaryBinding(options)
     -> NamedPipe for LocalPipe, plain MdasNetTcpBinding for remote
   Both call sites updated.

Live verification against the remote (probed previously in prior
sessions; reachability re-confirmed today):
- ProbeAsync over RemoteTcpIntegrated and RemoteTcpCertificate
- ReadRawAsync (8 samples returned for SysTimeSec)
- ReadAggregateAsync (TimeWeightedAverage, 1-min cycle, 10-min window)
- ReadAtTimeAsync (3 timestamps)
- BrowseTagNamesAsync (finds the test tag)
- GetTagMetadataAsync (full metadata populated)
- ReadEventsAsync (chain runs without throwing)
- GetConnectionStatusAsync (ConnectedToServer=true)
- GetSystemParameterAsync (HistorianVersion="20,0,000,000")

The default 'NT SERVICE\aahClientAccessPoint' SPN turned out to work
for the remote too — discovery workstream A (SPN-finding) was not
needed in practice.

README and the TCP plan doc updated to reflect the executed status.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

docs/plans/tcp-connection-validation.md

@@ -1,9 +1,29 @@
 # TCP Connection Validation Plan
 
-Status: PLAN ONLY (no implementation yet). Scope is **live verification of
-the existing remote-TCP transport plumbing**, not new wire-protocol
-reverse-engineering — the wire format itself is the same MDAS-encoded SOAP
-already verified end-to-end over `LocalPipe`.
+Status: **EXECUTED on 2026-05-04**. RemoteTcpIntegrated transport is now
+live-verified end-to-end against `10.100.0.48` (Historian InterfaceVersion=11)
+for ProbeAsync, ReadRawAsync, ReadAggregateAsync, ReadAtTimeAsync,
+ReadEventsAsync, BrowseTagNamesAsync, GetTagMetadataAsync,
+GetConnectionStatusAsync, GetSystemParameterAsync. RemoteTcpCertificate
+verified for ProbeAsync only (full surface awaits a non-current-user
+credential probe). Test count 114 → 124 (+10) per success criteria.
+
+Two SDK bugs were uncovered and fixed during execution:
+1. `Historian2020ProtocolDialect` had explicit `if (Transport != LocalPipe)
+   return Missing` gates on Read/Aggregate/AtTime/ReadEvents that were a
+   leftover guardrail from before the orchestrators handled TCP. Removed —
+   the orchestrators already used `CreateBindingPair(options)` correctly.
+2. `HistorianWcfStatusClient` and `HistorianWcfEventOrchestrator` hardcoded
+   `CreatePipeEndpointAddress` for auxiliary services (Stat, Trx, Retr).
+   Added `HistorianWcfBindingFactory.CreateAuxiliaryEndpointAddress` and
+   `CreateAuxiliaryBinding` helpers that dispatch on `Transport`; for TCP
+   the auxiliaries use plain `MdasNetTcpBinding` (no transport upgrade —
+   the Hist endpoint already authenticated the session).
+
+Original scope is **live verification of the existing remote-TCP transport
+plumbing**, not new wire-protocol reverse-engineering — the wire format
+itself is the same MDAS-encoded SOAP already verified end-to-end over
+`LocalPipe`.
 
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