Phase 6.2 Stream C follow-up — wire AuthorizationGate into DriverNodeManager Read / Write / HistoryRead dispatch

Closes the Phase 6.2 security gap the v2 release-readiness dashboard flagged:
the evaluator + trie + gate shipped as code in PRs #84-88 but no dispatch
path called them. This PR threads the gate end-to-end from
OpcUaApplicationHost → OtOpcUaServer → DriverNodeManager and calls it on
every Read / Write / 4 HistoryRead paths.

Server.Security additions:
- NodeScopeResolver — maps driver fullRef → Core.Authorization NodeScope.
  Phase 1 shape: populates ClusterId + TagId; leaves NamespaceId / UnsArea /
  UnsLine / Equipment null. The cluster-level ACL cascade covers this
  configuration (decision #129 additive grants). Finer-grained scope
  resolution (joining against the live Configuration DB for UnsArea / UnsLine
  path) lands as Stream C.12 follow-up.
- WriteAuthzPolicy.ToOpcUaOperation — maps SecurityClassification → the
  OpcUaOperation the gate evaluator consults (Operate/SecuredWrite →
  WriteOperate; Tune → WriteTune; Configure/VerifiedWrite → WriteConfigure).

DriverNodeManager wiring:
- Ctor gains optional AuthorizationGate + NodeScopeResolver; both null means
  the pre-Phase-6.2 dispatch runs unchanged (backwards-compat for every
  integration test that constructs DriverNodeManager directly).
- OnReadValue: ahead of the invoker call, builds NodeScope + calls
  gate.IsAllowed(identity, Read, scope). Denied reads return
  BadUserAccessDenied without hitting the driver.
- OnWriteValue: preserves the existing WriteAuthzPolicy check (classification
  vs session roles) + adds an additive gate check using
  WriteAuthzPolicy.ToOpcUaOperation(classification) to pick the right
  WriteOperate/Tune/Configure surface. Lax mode falls through for identities
  without LDAP groups.
- Four HistoryRead paths (Raw / Processed / AtTime / Events): gate check
  runs per-node before the invoker. Events path tolerates fullRef=null
  (event-history queries can target a notifier / driver-root; those are
  cluster-wide reads that need a different scope shape — deferred).
- New WriteAccessDenied helper surfaces BadUserAccessDenied in the
  OpcHistoryReadResult slot + errors list, matching the shape of the
  existing WriteUnsupported / WriteInternalError helpers.

OtOpcUaServer + OpcUaApplicationHost: gate + resolver thread through as
optional constructor parameters (same pattern as DriverResiliencePipelineBuilder
in Phase 6.1). Null defaults keep the existing 3 OpcUaApplicationHost
integration tests constructing without them unchanged.

Tests (5 new in NodeScopeResolverTests):
- Resolve populates ClusterId + TagId + Equipment Kind.
- Resolve leaves finer path null per Phase 1 shape (doc'd as follow-up).
- Empty fullReference throws.
- Empty clusterId throws at ctor.
- Resolver is stateless across calls.

The existing 9 AuthorizationGate tests (shipped in PR #86) continue to
cover the gate's allow/deny semantics under strict + lax mode.

Full solution dotnet test: 1164 passing (was 1159, +5). Pre-existing
Client.CLI Subscribe flake unchanged. Existing OpcUaApplicationHost +
HealthEndpointsHost + driver integration tests continue to pass because the
gate defaults to null → no enforcement, and the lax-mode fallback returns
true for identities without LDAP groups (the anonymous test path).

Production deployments flip the gate on by constructing it via
OpcUaApplicationHost's new authzGate parameter + setting
`Authorization:StrictMode = true` once ACL data is populated. Flipping the
switch post-seed turns the evaluator + trie from scaffolded code into
actual enforcement.

This closes release blocker #1 listed in docs/v2/v2-release-readiness.md.

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

tests/ZB.MOM.WW.OtOpcUa.Server.Tests/NodeScopeResolverTests.cs

@@ -0,0 +1,64 @@
+using Shouldly;
+using Xunit;
+using ZB.MOM.WW.OtOpcUa.Core.Authorization;
+using ZB.MOM.WW.OtOpcUa.Server.Security;
+
+namespace ZB.MOM.WW.OtOpcUa.Server.Tests;
+
+[Trait("Category", "Unit")]
+public sealed class NodeScopeResolverTests
+{
+    [Fact]
+    public void Resolve_PopulatesClusterAndTag()
+    {
+        var resolver = new NodeScopeResolver("c-warsaw");
+
+        var scope = resolver.Resolve("TestMachine_001/Oven/SetPoint");
+
+        scope.ClusterId.ShouldBe("c-warsaw");
+        scope.TagId.ShouldBe("TestMachine_001/Oven/SetPoint");
+        scope.Kind.ShouldBe(NodeHierarchyKind.Equipment);
+    }
+
+    [Fact]
+    public void Resolve_Leaves_UnsPath_Null_For_Phase1()
+    {
+        var resolver = new NodeScopeResolver("c-1");
+
+        var scope = resolver.Resolve("tag-1");
+
+        // Phase 1 flat scope — finer resolution tracked as Stream C.12 follow-up.
+        scope.NamespaceId.ShouldBeNull();
+        scope.UnsAreaId.ShouldBeNull();
+        scope.UnsLineId.ShouldBeNull();
+        scope.EquipmentId.ShouldBeNull();
+    }
+
+    [Fact]
+    public void Resolve_Throws_OnEmptyFullReference()
+    {
+        var resolver = new NodeScopeResolver("c-1");
+
+        Should.Throw<ArgumentException>(() => resolver.Resolve(""));
+        Should.Throw<ArgumentException>(() => resolver.Resolve("   "));
+    }
+
+    [Fact]
+    public void Ctor_Throws_OnEmptyClusterId()
+    {
+        Should.Throw<ArgumentException>(() => new NodeScopeResolver(""));
+    }
+
+    [Fact]
+    public void Resolver_IsStateless_AcrossCalls()
+    {
+        var resolver = new NodeScopeResolver("c");
+        var s1 = resolver.Resolve("tag-a");
+        var s2 = resolver.Resolve("tag-b");
+
+        s1.TagId.ShouldBe("tag-a");
+        s2.TagId.ShouldBe("tag-b");
+        s1.ClusterId.ShouldBe("c");
+        s2.ClusterId.ShouldBe("c");
+    }
+}