fix(historian-gateway): wire dormant GatewayTagProvisioner + provisioning observability/docs

PR #423 shipped GatewayTagProvisioner + unit tests but never registered it in
DI nor passed it into the AddressSpaceApplier, so deploying historized tags used
the no-op NullHistorianProvisioning and never called the gateway's EnsureTags
(confirmed live on wonder-app-vd03: zero EnsureTags calls on a historized deploy).
Addresses HISTORIAN-GATEWAY-INTEGRATION-ISSUES.md.

Issue 1 (wire provisioner):
- Runtime: AddHistorianProvisioning extension (gated on ServerHistorian:Enabled,
  mirrors AddServerHistorian) + NullHistorianProvisioning TryAdd default in
  AddOtOpcUaRuntime; WithOtOpcUaRuntimeActors resolves IHistorianProvisioning and
  passes it into the applier.
- Gateway driver: GatewayHistorian.CreateProvisioner factory (mirrors CreateDataSource).
- Host: Program.cs calls AddHistorianProvisioning after AddServerHistorian.
- Tests: AddHistorianProvisioningTests (config-gated registration + the
  register->resolve->applier->EnsureTags chain).

Issue 2 (observability): AddressSpaceApplier logs the provisioning tally on every
successful dispatch (was gated behind Failed/Skipped > 0), including dispatched=N
so a dispatched=N/requested=0 line flags the dormant no-op. +2 tests.

Issue 3 (30s HistoryRead on unprovisioned tags): root coupling fixed by Issue 1;
documented the CallTimeout knob + coupling. Default left at 30s pending the
multi-data-point investigation the issue requests (lowering risks truncating
legitimate large reads).

Issue 4 (docs): docs/Historian.md gains a "Tag auto-provisioning (EnsureTags)"
section and CLAUDE.md a wiring/gating note (both stress ServerHistorian:Enabled).
Sibling scadaproj/CLAUDE.md carries no false claim -> unchanged.

Pre-existing Serilog observation: anchor CWD to AppContext.BaseDirectory before
AddZbSerilog so the relative file sink stops landing in C:\Windows\System32 under
the Windows-service CWD.

Builds 0-error; Runtime.Tests 355, OpcUaServer.Tests 329, Gateway.Tests 99 (+4
live-skipped) all green.

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Historian.Gateway/GatewayHistorianServiceCollectionExtensions.cs

@@ -78,4 +78,40 @@ public static class GatewayHistorian
             HistorianGatewayClientAdapter.Create(options, loggerFactory),
             logger);
     }
+
+    /// <summary>
+    ///     Builds a <see cref="GatewayTagProvisioner"/> over a lazily connected
+    ///     <see cref="HistorianGatewayClientAdapter"/> mapped from the bound
+    ///     <see cref="ServerHistorianOptions"/> — the <b>same single gateway</b> the read path
+    ///     (<see cref="CreateDataSource"/>) and alarm-write path (<see cref="CreateAlarmWriter"/>) target. The
+    ///     Host's <c>AddHistorianProvisioning</c> wiring supplies this as the concrete
+    ///     <see cref="IHistorianProvisioning"/> the <c>AddressSpaceApplier</c> calls (non-blocking
+    ///     <c>EnsureTags</c>) when a deploy adds historized tags, so a brand-new historized tag exists in the
+    ///     historian before the recorder's <c>WriteLiveValues</c> land. Resolves an <see cref="ILoggerFactory"/>
+    ///     and the provisioner's <see cref="ILogger{TCategoryName}"/> from <paramref name="services"/>, falling
+    ///     back to the null implementations when absent. Performs no network I/O — the underlying channel dials
+    ///     on first <c>EnsureTags</c>.
+    /// </summary>
+    /// <remarks>
+    ///     Like <see cref="CreateAlarmWriter"/>, this constructs its <b>own</b>
+    ///     <see cref="HistorianGatewayClientAdapter"/> — a separate gRPC channel to the same gateway. A second
+    ///     channel to a co-located sidecar is cheap (the gateway pools the historian sessions server-side), and
+    ///     it keeps each path's channel lifetime clean and independent.
+    /// </remarks>
+    /// <param name="options">The bound <c>ServerHistorian</c> configuration (endpoint, key, TLS posture).</param>
+    /// <param name="services">The resolving service provider (used only to locate logging services).</param>
+    /// <returns>The gateway-backed <see cref="IHistorianProvisioning"/>.</returns>
+    public static IHistorianProvisioning CreateProvisioner(ServerHistorianOptions options, IServiceProvider services)
+    {
+        ArgumentNullException.ThrowIfNull(options);
+        ArgumentNullException.ThrowIfNull(services);
+
+        var loggerFactory = services.GetService<ILoggerFactory>() ?? NullLoggerFactory.Instance;
+        var logger = services.GetService<ILogger<GatewayTagProvisioner>>()
+            ?? NullLogger<GatewayTagProvisioner>.Instance;
+
+        return new GatewayTagProvisioner(
+            HistorianGatewayClientAdapter.Create(options, loggerFactory),
+            logger);
+    }
 }