Phase 0 — mechanical rename ZB.MOM.WW.LmxOpcUa.* → ZB.MOM.WW.OtOpcUa.*

Renames all 11 projects (5 src + 6 tests), the .slnx solution file, all source-file namespaces, all axaml namespace references, and all v1 documentation references in CLAUDE.md and docs/*.md (excluding docs/v2/ which is already in OtOpcUa form). Also updates the TopShelf service registration name from "LmxOpcUa" to "OtOpcUa" per Phase 0 Task 0.6.

Preserves runtime identifiers per Phase 0 Out-of-Scope rules to avoid breaking v1/v2 client trust during coexistence: OPC UA `ApplicationUri` defaults (`urn:{GalaxyName}:LmxOpcUa`), server `EndpointPath` (`/LmxOpcUa`), `ServerName` default (feeds cert subject CN), `MxAccessConfiguration.ClientName` default (defensive — stays "LmxOpcUa" for MxAccess audit-trail consistency), client OPC UA identifiers (`ApplicationName = "LmxOpcUaClient"`, `ApplicationUri = "urn:localhost:LmxOpcUaClient"`, cert directory `%LocalAppData%\LmxOpcUaClient\pki\`), and the `LmxOpcUaServer` class name (class rename out of Phase 0 scope per Task 0.5 sed pattern; happens in Phase 1 alongside `LmxNodeManager → GenericDriverNodeManager` Core extraction). 23 LmxOpcUa references retained, all enumerated and justified in `docs/v2/implementation/exit-gate-phase-0.md`.

Build clean: 0 errors, 30 warnings (lower than baseline 167). Tests at strict improvement over baseline: 821 passing / 1 failing vs baseline 820 / 2 (one flaky pre-existing failure passed this run; the other still fails — both pre-existing and unrelated to the rename). `Client.UI.Tests`, `Historian.Aveva.Tests`, `Client.Shared.Tests`, `IntegrationTests` all match baseline exactly. Exit gate compliance results recorded in `docs/v2/implementation/exit-gate-phase-0.md` with all 7 checks PASS or DEFERRED-to-PR-review (#7 service install verification needs Windows service permissions on the reviewer's box).

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

tests/ZB.MOM.WW.OtOpcUa.Tests/GalaxyRepository/ChangeDetectionServiceTests.cs

@@ -0,0 +1,118 @@
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+using Shouldly;
+using Xunit;
+using ZB.MOM.WW.OtOpcUa.Host.GalaxyRepository;
+using ZB.MOM.WW.OtOpcUa.Tests.Helpers;
+
+namespace ZB.MOM.WW.OtOpcUa.Tests.GalaxyRepository
+{
+    /// <summary>
+    ///     Verifies the polling service that detects Galaxy deploy changes and triggers address-space rebuilds.
+    /// </summary>
+    public class ChangeDetectionServiceTests
+    {
+        /// <summary>
+        ///     Confirms that the first poll always triggers an initial rebuild notification.
+        /// </summary>
+        [Fact]
+        public async Task FirstPoll_AlwaysTriggers()
+        {
+            var repo = new FakeGalaxyRepository { LastDeployTime = new DateTime(2024, 1, 1) };
+            var service = new ChangeDetectionService(repo, 1);
+            var triggered = false;
+            service.OnGalaxyChanged += () => triggered = true;
+
+            service.Start();
+            await Task.Delay(500);
+            service.Stop();
+
+            triggered.ShouldBe(true);
+            service.Dispose();
+        }
+
+        /// <summary>
+        ///     Confirms that repeated polls with the same deploy timestamp do not retrigger rebuilds.
+        /// </summary>
+        [Fact]
+        public async Task SameTimestamp_DoesNotTriggerAgain()
+        {
+            var repo = new FakeGalaxyRepository { LastDeployTime = new DateTime(2024, 1, 1) };
+            var service = new ChangeDetectionService(repo, 1);
+            var triggerCount = 0;
+            service.OnGalaxyChanged += () => Interlocked.Increment(ref triggerCount);
+
+            service.Start();
+            await Task.Delay(2500); // Should have polled at least twice
+            service.Stop();
+
+            triggerCount.ShouldBe(1); // Only the first poll
+            service.Dispose();
+        }
+
+        /// <summary>
+        ///     Confirms that a changed deploy timestamp triggers another rebuild notification.
+        /// </summary>
+        [Fact]
+        public async Task ChangedTimestamp_TriggersAgain()
+        {
+            var repo = new FakeGalaxyRepository { LastDeployTime = new DateTime(2024, 1, 1) };
+            var service = new ChangeDetectionService(repo, 1);
+            var triggerCount = 0;
+            service.OnGalaxyChanged += () => Interlocked.Increment(ref triggerCount);
+
+            service.Start();
+            await Task.Delay(500);
+
+            // Change the deploy time
+            repo.LastDeployTime = new DateTime(2024, 2, 1);
+            await Task.Delay(1500);
+            service.Stop();
+
+            triggerCount.ShouldBeGreaterThanOrEqualTo(2);
+            service.Dispose();
+        }
+
+        /// <summary>
+        ///     Confirms that transient polling failures do not crash the service and allow later recovery.
+        /// </summary>
+        [Fact]
+        public async Task FailedPoll_DoesNotCrash_RetriesNext()
+        {
+            var repo = new FakeGalaxyRepository { LastDeployTime = new DateTime(2024, 1, 1) };
+            var service = new ChangeDetectionService(repo, 1);
+            var triggerCount = 0;
+            service.OnGalaxyChanged += () => Interlocked.Increment(ref triggerCount);
+
+            service.Start();
+            await Task.Delay(500);
+
+            // Make it fail
+            repo.ShouldThrow = true;
+            await Task.Delay(1500);
+
+            // Restore and it should recover
+            repo.ShouldThrow = false;
+            repo.LastDeployTime = new DateTime(2024, 3, 1);
+            await Task.Delay(1500);
+            service.Stop();
+
+            // Should have triggered at least on first poll and on the changed timestamp
+            triggerCount.ShouldBeGreaterThanOrEqualTo(1);
+            service.Dispose();
+        }
+
+        /// <summary>
+        ///     Confirms that stopping the service before it starts is a harmless no-op.
+        /// </summary>
+        [Fact]
+        public void Stop_BeforeStart_DoesNotThrow()
+        {
+            var repo = new FakeGalaxyRepository();
+            var service = new ChangeDetectionService(repo, 30);
+            service.Stop(); // Should not throw
+            service.Dispose();
+        }
+    }
+}