feat(audit): MxGateway IAuditActorAccessor + dashboard audit Actor = operator principal (keyId→Target) (Phase 3)

Introduce IAuditActorAccessor seam + HttpAuditActorAccessor impl (reads ZbClaimTypes.Username
from IHttpContextAccessor; falls back to Identity.Name / ZbClaimTypes.Name; null when
unauthenticated). Register in DI via DashboardServiceCollectionExtensions.

Wire DashboardApiKeyManagementService: WriteDashboardAuditAsync now accepts the ClaimsPrincipal
user already in scope at each call site; ResolveOperatorActor extracts ZbClaimTypes.Username
(preferred) or Identity.Name. All four dashboard-* events now emit Actor = LDAP operator
username and Target = managed keyId, fixing the semantic gap where both fields held the keyId.

ConstraintEnforcer (gRPC / API-key actor) and CanonicalForwardingApiKeyAuditStore (CLI /
"system"/"cli" fallback) are unchanged.

Tests: DashboardApiKeyManagementServiceTests updated — CreateAuthorizedUser adds ZbClaimTypes.Username
("alice"), all dashboard-* audit assertions updated to Actor = "alice" / Target = "operator01";
new CreateAsync_AuthorizedUser_CanonicalAuditEventHasOperatorAsActorAndKeyIdAsTarget verifies the
canonical AuditEvent directly. New HttpAuditActorAccessorTests (4 cases: username claim, Identity.Name
fallback, unauthenticated → null, no context → null). ConstraintEnforcer tests still assert API-key/anonymous actor.

src/ZB.MOM.WW.MxGateway.Tests/Gateway/Dashboard/DashboardApiKeyManagementServiceTests.cs

@@ -4,8 +4,10 @@ using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 using ZB.MOM.WW.Auth.Abstractions.ApiKeys;
 using ZB.MOM.WW.Auth.ApiKeys.Admin;
+using ZB.MOM.WW.Auth.AspNetCore;
 using ZB.MOM.WW.MxGateway.Server.Configuration;
 using ZB.MOM.WW.MxGateway.Server.Dashboard;
+using ZB.MOM.WW.MxGateway.Server.Security.Audit;
 using ZB.MOM.WW.MxGateway.Server.Security.Authentication;
 using ZB.MOM.WW.MxGateway.Server.Security.Authorization;
 using ZB.MOM.WW.MxGateway.Tests.Security.Authentication;
@@ -70,7 +72,10 @@ public sealed class DashboardApiKeyManagementServiceTests : IDisposable
         Assert.Equal(["Area1/*"], gatewayIdentity.EffectiveConstraints.BrowseSubtrees);
 
         IReadOnlyList<ApiKeyAuditEntry> audit = await ListAuditAsync(services);
-        Assert.Contains(audit, entry => entry.EventType == "dashboard-create-key" && entry.KeyId == "operator01");
+        // Phase 3: Actor = operator username ("alice"), Target = managed keyId ("operator01").
+        Assert.Contains(audit, entry =>
+            entry.EventType == "dashboard-create-key"
+            && entry.KeyId == "alice");
     }
 
     /// <summary>Verifies that creating a key whose id already exists is rejected.</summary>
@@ -107,9 +112,11 @@ public sealed class DashboardApiKeyManagementServiceTests : IDisposable
         ApiKeyListItem key = Assert.Single(await ListAsync(services));
         Assert.NotNull(key.RevokedUtc);
         IReadOnlyList<ApiKeyAuditEntry> audit = await ListAuditAsync(services);
+        // Phase 3: Actor = operator username; the dashboard-revoke-key event surfaces KeyId = "alice"
+        // (the operator) and Details = "revoked".
         Assert.Contains(audit, entry =>
             entry.EventType == "dashboard-revoke-key"
-            && entry.KeyId == "operator01"
+            && entry.KeyId == "alice"
             && entry.Details == "revoked");
     }
 
@@ -138,9 +145,10 @@ public sealed class DashboardApiKeyManagementServiceTests : IDisposable
         Assert.True((await verifier.VerifyAsync($"Bearer {result.ApiKey}", CancellationToken.None)).Succeeded);
 
         IReadOnlyList<ApiKeyAuditEntry> audit = await ListAuditAsync(services);
+        // Phase 3: Actor = operator username ("alice").
         Assert.Contains(audit, entry =>
             entry.EventType == "dashboard-rotate-key"
-            && entry.KeyId == "operator01"
+            && entry.KeyId == "alice"
             && entry.Details == "rotated");
     }
 
@@ -161,9 +169,10 @@ public sealed class DashboardApiKeyManagementServiceTests : IDisposable
         Assert.True(result.Succeeded);
         Assert.Empty(await ListAsync(services));
         IReadOnlyList<ApiKeyAuditEntry> audit = await ListAuditAsync(services);
+        // Phase 3: Actor = operator username ("alice").
         Assert.Contains(audit, entry =>
             entry.EventType == "dashboard-delete-key"
-            && entry.KeyId == "operator01"
+            && entry.KeyId == "alice"
             && entry.Details == "deleted");
     }
 
@@ -190,7 +199,8 @@ public sealed class DashboardApiKeyManagementServiceTests : IDisposable
         IReadOnlyList<ApiKeyAuditEntry> audit = await ListAuditAsync(services);
         ApiKeyAuditEntry deleteEntry = Assert.Single(
             audit, entry => entry.EventType == "dashboard-delete-key");
-        Assert.Equal("operator01", deleteEntry.KeyId);
+        // Phase 3: Actor = operator username ("alice"), not the managed keyId.
+        Assert.Equal("alice", deleteEntry.KeyId);
         Assert.Equal("not-found-or-active", deleteEntry.Details);
     }
 
@@ -241,6 +251,44 @@ public sealed class DashboardApiKeyManagementServiceTests : IDisposable
         Assert.Empty(await ListAsync(services));
     }
 
+    /// <summary>
+    /// Phase 3 canonical audit shape: the dashboard-create-key canonical AuditEvent records
+    /// the operator username as Actor and the managed keyId as Target.
+    /// </summary>
+    [Fact]
+    public async Task CreateAsync_AuthorizedUser_CanonicalAuditEventHasOperatorAsActorAndKeyIdAsTarget()
+    {
+        await using ServiceProvider services = BuildServices();
+
+        // Wire a recording writer so we can inspect the canonical AuditEvent directly (bypassing
+        // the CanonicalForwardingApiKeyAuditStore round-trip that ListAuditAsync uses).
+        RecordingAuditWriter recordingWriter = new();
+        DefaultHttpContext httpContext = new();
+        httpContext.Connection.RemoteIpAddress = System.Net.IPAddress.Loopback;
+
+        DashboardApiKeyManagementService service = new(
+            new DashboardApiKeyAuthorization(),
+            services.GetRequiredService<ApiKeyAdminCommands>(),
+            services.GetRequiredService<IApiKeyAdminStore>(),
+            recordingWriter,
+            new HttpContextAccessor { HttpContext = httpContext });
+
+        await service.CreateAsync(
+            CreateAuthorizedUser(),
+            CreateRequest(),
+            CancellationToken.None);
+
+        // The dashboard-create-key event emitted directly by the service (not the library's
+        // create-key event forwarded via the adapter) must have Actor = operator username and
+        // Target = managed keyId.
+        ZB.MOM.WW.Audit.AuditEvent dashboardEvent = Assert.Single(
+            recordingWriter.Events,
+            e => e.Action == "dashboard-create-key");
+        Assert.Equal("alice", dashboardEvent.Actor);
+        Assert.Equal("operator01", dashboardEvent.Target);
+        Assert.Equal(ZB.MOM.WW.Audit.AuditOutcome.Success, dashboardEvent.Outcome);
+    }
+
     private DashboardApiKeyManagementService CreateService(ServiceProvider services)
     {
         DefaultHttpContext httpContext = new();
@@ -307,8 +355,13 @@ public sealed class DashboardApiKeyManagementServiceTests : IDisposable
 
     private static ClaimsPrincipal CreateAuthorizedUser()
     {
+        // Phase 3: include ZbClaimTypes.Username so ResolveOperatorActor picks up the LDAP
+        // login name ("alice") as the audit Actor. The keyId ("operator01") is the Target.
         ClaimsIdentity identity = new(
-            [new Claim(ClaimTypes.Role, DashboardRoles.Admin)],
+            [
+                new Claim(ClaimTypes.Role, DashboardRoles.Admin),
+                new Claim(ZbClaimTypes.Username, "alice"),
+            ],
             DashboardAuthenticationDefaults.AuthenticationScheme,
             ClaimTypes.Name,
             ClaimTypes.Role);
@@ -326,4 +379,18 @@ public sealed class DashboardApiKeyManagementServiceTests : IDisposable
 
         _tempDirectories.Clear();
     }
+
+    /// <summary>In-memory <see cref="ZB.MOM.WW.Audit.IAuditWriter"/> that records every event.</summary>
+    private sealed class RecordingAuditWriter : ZB.MOM.WW.Audit.IAuditWriter
+    {
+        /// <summary>Gets the recorded canonical audit events.</summary>
+        public List<ZB.MOM.WW.Audit.AuditEvent> Events { get; } = [];
+
+        /// <inheritdoc />
+        public Task WriteAsync(ZB.MOM.WW.Audit.AuditEvent auditEvent, CancellationToken cancellationToken = default)
+        {
+            Events.Add(auditEvent);
+            return Task.CompletedTask;
+        }
+    }
 }