docs(historian-gateway): document gateway backend, config keys, EnsureTags hook, known gates; retire Wonderware from docs

HistorianGateway is now the sole historian backend (read + alarm SendEvent +
continuous WriteLiveValues). Document the final state and retire the Wonderware
sidecar from the docs/config/labels:

- CLAUDE.md: rewrite the Historian section — ServerHistorian /
  ContinuousHistorization / AlarmHistorian config keys, the IHistorianProvisioning
  EnsureTags hook, the GatewayAlarmHistorianWriter SendEvent path + ReadEvents
  dependency on gateway RuntimeDb:EventReadsEnabled=true, gateway-side
  prerequisites (RuntimeDb flags + historian:read/write/tags:write scopes),
  migration note, and two KNOWN-LIMITATION callouts (live-validation gate +
  empty historized-ref-set recorder follow-on).
- appsettings.json: fix the stale ServerHistorian block (Host/Port/SharedSecret/
  ServerCertThumbprint -> Endpoint/ApiKey/UseTls/AllowUntrustedServerCertificate/
  CaCertificatePath/CallTimeout, keep MaxTieClusterOverfetch); add a disabled
  ContinuousHistorization block; prune the orphaned Wonderware keys from
  AlarmHistorian (keep the SQLite knobs). ApiKey env-supplied via
  ServerHistorian__ApiKey (commented; valid strict JSON via _comment keys).
- README.md + docs (Historian.md, AlarmHistorian.md, Configuration.md,
  ServiceHosting.md, DriverLifecycle.md, drivers/README.md, Uns.md, VirtualTags.md,
  AlarmTracking.md, Client.UI.md, README.md, TestConnectProbes.md): retire the
  Wonderware historian backend from current-backend descriptions; fix the stale
  ServerHistorian/AlarmHistorian config tables (now gateway shape); convert
  drivers/Historian.Wonderware.md to a retired stub pointing at the gateway.
- Source/UI labels (descriptive text only, no behavior change):
  OtOpcUaServerHostedService.cs, HistoryPaging.cs, OtOpcUaSdkServer.cs,
  HistorianAdapterActor.cs, VirtualTagModal.razor, ScriptedAlarmModal.razor,
  AlarmsHistorian.razor now name the HistorianGateway backend.

Build clean (0 errors); AdminUI.Tests green (514 passed).

Claude-Session: https://claude.ai/code/session_012SDSQ3AcaXqPcBtDESBRii

src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Pages/AlarmsHistorian.razor

@@ -18,8 +18,8 @@
 <section class="panel notice rise" style="animation-delay:.02s">
     Snapshot from the local node's <span class="mono">HistorianAdapterActor</span>. Default sink
     is a no-op (<span class="mono">NullAlarmHistorianSink</span>); production wires
-    <span class="mono">SqliteStoreAndForwardSink</span> with the Wonderware historian sidecar
-    behind it. Polling every @PollSeconds s.
+    <span class="mono">SqliteStoreAndForwardSink</span> draining to the HistorianGateway
+    (<span class="mono">SendEvent</span>) behind it. Polling every @PollSeconds s.
 </section>
 
 @if (_status is null)

src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Shared/Uns/ScriptedAlarmModal.razor

@@ -74,7 +74,7 @@
                                 <label class="form-label">HistorizeToAveva</label>
                                 <div class="form-check form-switch">
                                     <InputCheckbox @bind-Value="_form.HistorizeToAveva" class="form-check-input" />
-                                    <label class="form-check-label">Route to Wonderware sidecar</label>
+                                    <label class="form-check-label">Route to HistorianGateway</label>
                                 </div>
                             </div>
                             <div class="col-md-4 mb-3">

src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Shared/Uns/VirtualTagModal.razor

@@ -136,7 +136,7 @@
                                 <label class="form-label">Historize</label>
                                 <div class="form-check form-switch">
                                     <InputCheckbox @bind-Value="_form.Historize" class="form-check-input" />
-                                    <label class="form-check-label">Send to Wonderware historian</label>
+                                    <label class="form-check-label">Send to HistorianGateway</label>
                                 </div>
                             </div>
                         </div>