feat(centralui): execution-chain tree view on the Audit Log page

tests/ScadaLink.CentralUI.Tests/Services/AuditLogQueryServiceTests.cs

@@ -222,6 +222,66 @@ public class AuditLogQueryServiceTests
         Assert.NotSame(resolvedRepos[0], resolvedRepos[1]);
     }
 
+    // ─────────────────────────────────────────────────────────────────────────
+    // Audit Log ParentExecutionId feature (Task 10): GetExecutionTreeAsync —
+    // a thin pass-through over IAuditLogRepository.GetExecutionTreeAsync, mirroring
+    // QueryAsync's scope-per-call contract on the production path.
+    // ─────────────────────────────────────────────────────────────────────────
+
+    [Fact]
+    public async Task GetExecutionTreeAsync_ForwardsExecutionId_ToRepository()
+    {
+        var repo = Substitute.For<IAuditLogRepository>();
+        var executionId = Guid.Parse("aaaaaaaa-bbbb-cccc-dddd-eeeeeeeeeeee");
+        var expected = new List<ExecutionTreeNode>
+        {
+            new(executionId, null, 3,
+                new[] { "ApiOutbound" }, new[] { "Delivered" },
+                "plant-a", "boiler-3",
+                new DateTime(2026, 5, 20, 12, 0, 0, DateTimeKind.Utc),
+                new DateTime(2026, 5, 20, 12, 0, 5, DateTimeKind.Utc)),
+        };
+        repo.GetExecutionTreeAsync(executionId, Arg.Any<CancellationToken>())
+            .Returns(Task.FromResult<IReadOnlyList<ExecutionTreeNode>>(expected));
+
+        var sut = new AuditLogQueryService(repo, EmptyAggregator());
+
+        var result = await sut.GetExecutionTreeAsync(executionId);
+
+        Assert.Same(expected, result);
+        await repo.Received(1).GetExecutionTreeAsync(executionId, Arg.Any<CancellationToken>());
+    }
+
+    [Fact]
+    public async Task GetExecutionTreeAsync_OpensFreshScopePerCall_OnProductionCtor()
+    {
+        // The production ctor must resolve a fresh repository per call — same
+        // scope-per-query contract QueryAsync upholds, so the page's auto-load
+        // never shares the circuit-scoped DbContext.
+        var resolvedRepos = new List<IAuditLogRepository>();
+
+        var services = new ServiceCollection();
+        services.AddScoped<IAuditLogRepository>(_ =>
+        {
+            var repo = Substitute.For<IAuditLogRepository>();
+            repo.GetExecutionTreeAsync(Arg.Any<Guid>(), Arg.Any<CancellationToken>())
+                .Returns(Task.FromResult<IReadOnlyList<ExecutionTreeNode>>(Array.Empty<ExecutionTreeNode>()));
+            resolvedRepos.Add(repo);
+            return repo;
+        });
+
+        await using var provider = services.BuildServiceProvider();
+        var sut = new AuditLogQueryService(
+            provider.GetRequiredService<IServiceScopeFactory>(),
+            EmptyAggregator());
+
+        await sut.GetExecutionTreeAsync(Guid.NewGuid());
+        await sut.GetExecutionTreeAsync(Guid.NewGuid());
+
+        Assert.Equal(2, resolvedRepos.Count);
+        Assert.NotSame(resolvedRepos[0], resolvedRepos[1]);
+    }
+
     private static SiteHealthState StateWithBacklog(string siteId, int? pending)
     {
         SiteAuditBacklogSnapshot? backlog = pending.HasValue