Resolve IntegrationTests-022..024

IntegrationTests-022 (Conventions): ResolveRepositoryRoot now throws
InvalidOperationException when the walk exhausts without finding a root
marker, with a message naming the start directory, the expected markers
(src/, .git, *.sln, *.slnx), and the MXGATEWAY_LIVE_MXACCESS_WORKER_EXE
escape hatch. Replaces the silent fallback to
Directory.GetCurrentDirectory() that previously masked misconfiguration.
New regression test
ResolveRepositoryRoot_NoMarkers_ThrowsInvalidOperationExceptionNamingStartAndMarkers
in IntegrationTestEnvironmentTests asserts the throw and the message
contents. TDD red→green confirmed.

IntegrationTests-023 (Testing coverage): DashboardLdapLiveTests's
AuthenticateAsync_AdminInGwAdminGroup_Succeeds now asserts that the
authenticated principal carries a ClaimTypes.Role claim with value
DashboardRoles.Admin in addition to the existing LdapGroupClaimType
assertion. A regression in MapGroupsToRoles (returning an empty list or
missing the RDN fallback) would now surface here. Gated by
MXGATEWAY_RUN_LIVE_LDAP_TESTS.

IntegrationTests-024 (Conventions): Option (b) — extracted within
IntegrationTests. New file TestSupport/NullDashboardEventBroadcaster.cs
(public type, private ctor, singleton Instance). The inline class at
the bottom of WorkerLiveMxAccessSmokeTests is gone; the file now imports
the shared type. Matches the unit-test project's Tests-007 / Tests-021 /
Tests-025 pattern while keeping the two test projects independently
buildable (no shared test-helpers project crossing module boundaries).

Verification: dotnet build src/ZB.MOM.WW.MxGateway.IntegrationTests
clean; 19/19 integration tests passing (live MxAccess + LDAP + Galaxy).

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

src/ZB.MOM.WW.MxGateway.IntegrationTests/IntegrationTestEnvironmentTests.cs

@@ -45,4 +45,41 @@ public sealed class IntegrationTestEnvironmentTests
             }
         }
     }
+
+    /// <summary>
+    /// Verifies that <see cref="IntegrationTestEnvironment.ResolveRepositoryRoot"/>
+    /// throws <see cref="InvalidOperationException"/> with a diagnostic message when
+    /// the walk exhausts without finding a repository root. The previous silent
+    /// fallback to <c>Directory.GetCurrentDirectory()</c> masked misconfiguration
+    /// (IntegrationTests-022); operators get a clear, actionable failure instead.
+    /// </summary>
+    [Fact]
+    public void ResolveRepositoryRoot_NoMarkers_ThrowsInvalidOperationExceptionNamingStartAndMarkers()
+    {
+        string isolatedRoot = Path.Combine(Path.GetTempPath(), Path.GetRandomFileName());
+        string isolatedStart = Path.Combine(isolatedRoot, "nested");
+
+        try
+        {
+            Directory.CreateDirectory(isolatedStart);
+
+            InvalidOperationException ex = Assert.Throws<InvalidOperationException>(
+                () => IntegrationTestEnvironment.ResolveRepositoryRoot(isolatedStart));
+
+            Assert.Contains(isolatedStart, ex.Message, StringComparison.Ordinal);
+            Assert.Contains(".git", ex.Message, StringComparison.Ordinal);
+            Assert.Contains(".sln", ex.Message, StringComparison.Ordinal);
+            Assert.Contains(
+                IntegrationTestEnvironment.LiveMxAccessWorkerExecutableVariableName,
+                ex.Message,
+                StringComparison.Ordinal);
+        }
+        finally
+        {
+            if (Directory.Exists(isolatedRoot))
+            {
+                Directory.Delete(isolatedRoot, recursive: true);
+            }
+        }
+    }
 }