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>

src/ZB.MOM.WW.OtOpcUa.Host/GalaxyRepository/ChangeDetectionService.cs

@@ -0,0 +1,124 @@
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+using Serilog;
+using ZB.MOM.WW.OtOpcUa.Host.Domain;
+
+namespace ZB.MOM.WW.OtOpcUa.Host.GalaxyRepository
+{
+    /// <summary>
+    ///     Polls the Galaxy database for deployment changes and fires OnGalaxyChanged. (GR-003, GR-004)
+    /// </summary>
+    public class ChangeDetectionService : IDisposable
+    {
+        private static readonly ILogger Log = Serilog.Log.ForContext<ChangeDetectionService>();
+        private readonly int _intervalSeconds;
+
+        private readonly IGalaxyRepository _repository;
+        private CancellationTokenSource? _cts;
+        private Task? _pollTask;
+
+        /// <summary>
+        ///     Initializes a new change detector for Galaxy deploy timestamps.
+        /// </summary>
+        /// <param name="repository">The repository used to query the latest deploy timestamp.</param>
+        /// <param name="intervalSeconds">The polling interval, in seconds, between deploy checks.</param>
+        /// <param name="initialDeployTime">An optional deploy timestamp already known at service startup.</param>
+        public ChangeDetectionService(IGalaxyRepository repository, int intervalSeconds,
+            DateTime? initialDeployTime = null)
+        {
+            _repository = repository;
+            _intervalSeconds = intervalSeconds;
+            LastKnownDeployTime = initialDeployTime;
+        }
+
+        /// <summary>
+        ///     Gets the last deploy timestamp observed by the polling loop.
+        /// </summary>
+        public DateTime? LastKnownDeployTime { get; private set; }
+
+        /// <summary>
+        ///     Stops the polling loop and disposes the underlying cancellation resources.
+        /// </summary>
+        public void Dispose()
+        {
+            Stop();
+            _cts?.Dispose();
+        }
+
+        /// <summary>
+        ///     Occurs when a new Galaxy deploy timestamp indicates the OPC UA address space should be rebuilt.
+        /// </summary>
+        public event Action? OnGalaxyChanged;
+
+        /// <summary>
+        ///     Starts the background polling loop that watches for Galaxy deploy changes.
+        /// </summary>
+        public void Start()
+        {
+            if (_cts != null)
+                Stop();
+
+            _cts = new CancellationTokenSource();
+            _pollTask = Task.Run(() => PollLoopAsync(_cts.Token));
+            Log.Information("Change detection started (interval={Interval}s)", _intervalSeconds);
+        }
+
+        /// <summary>
+        ///     Stops the background polling loop.
+        /// </summary>
+        public void Stop()
+        {
+            _cts?.Cancel();
+            try { _pollTask?.Wait(TimeSpan.FromSeconds(5)); } catch { /* timeout or faulted */ }
+            _pollTask = null;
+            Log.Information("Change detection stopped");
+        }
+
+        private async Task PollLoopAsync(CancellationToken ct)
+        {
+            // If no initial deploy time was provided, first poll triggers unconditionally
+            var firstPoll = LastKnownDeployTime == null;
+
+            while (!ct.IsCancellationRequested)
+            {
+                try
+                {
+                    var deployTime = await _repository.GetLastDeployTimeAsync(ct);
+
+                    if (firstPoll)
+                    {
+                        firstPoll = false;
+                        LastKnownDeployTime = deployTime;
+                        Log.Information("Initial deploy time: {DeployTime}", deployTime);
+                        OnGalaxyChanged?.Invoke();
+                    }
+                    else if (deployTime != LastKnownDeployTime)
+                    {
+                        Log.Information("Galaxy deployment change detected: {Previous} → {Current}",
+                            LastKnownDeployTime, deployTime);
+                        LastKnownDeployTime = deployTime;
+                        OnGalaxyChanged?.Invoke();
+                    }
+                }
+                catch (OperationCanceledException)
+                {
+                    break;
+                }
+                catch (Exception ex)
+                {
+                    Log.Warning(ex, "Change detection poll failed, will retry next interval");
+                }
+
+                try
+                {
+                    await Task.Delay(TimeSpan.FromSeconds(_intervalSeconds), ct);
+                }
+                catch (OperationCanceledException)
+                {
+                    break;
+                }
+            }
+        }
+    }
+}