chore: organize solution into module folders (Core/Server/Drivers/Client/Tooling)

Group all 69 projects into category subfolders under src/ and tests/ so the
Rider Solution Explorer mirrors the module structure. Folders: Core, Server,
Drivers (with a nested Driver CLIs subfolder), Client, Tooling.

- Move every project folder on disk with git mv (history preserved as renames).
- Recompute relative paths in 57 .csproj files: cross-category ProjectReferences,
  the lib/ HintPath+None refs in Driver.Historian.Wonderware, and the external
  mxaccessgw refs in Driver.Galaxy and its test project.
- Rebuild ZB.MOM.WW.OtOpcUa.slnx with nested solution folders.
- Re-prefix project paths in functional scripts (e2e, compliance, smoke SQL,
  integration, install).

Build green (0 errors); unit tests pass. Docs left for a separate pass.

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

tests/Core/ZB.MOM.WW.OtOpcUa.Core.Tests/Resilience/AlarmSurfaceInvokerTests.cs

@@ -0,0 +1,127 @@
+using Shouldly;
+using Xunit;
+using ZB.MOM.WW.OtOpcUa.Core.Abstractions;
+using ZB.MOM.WW.OtOpcUa.Core.Resilience;
+
+namespace ZB.MOM.WW.OtOpcUa.Core.Tests.Resilience;
+
+[Trait("Category", "Unit")]
+public sealed class AlarmSurfaceInvokerTests
+{
+    private static readonly DriverResilienceOptions TierAOptions = new() { Tier = DriverTier.A };
+
+    [Fact]
+    public async Task SubscribeAsync_EmptyList_ReturnsEmpty_WithoutDriverCall()
+    {
+        var driver = new FakeAlarmSource();
+        var surface = NewSurface(driver, defaultHost: "h");
+
+        var handles = await surface.SubscribeAsync([], CancellationToken.None);
+
+        handles.Count.ShouldBe(0);
+        driver.SubscribeCallCount.ShouldBe(0);
+    }
+
+    [Fact]
+    public async Task SubscribeAsync_SingleHost_RoutesThroughDefaultHost()
+    {
+        var driver = new FakeAlarmSource();
+        var surface = NewSurface(driver, defaultHost: "h1");
+
+        var handles = await surface.SubscribeAsync(["src-1", "src-2"], CancellationToken.None);
+
+        handles.Count.ShouldBe(1);
+        driver.SubscribeCallCount.ShouldBe(1);
+        driver.LastSubscribedIds.ShouldBe(["src-1", "src-2"]);
+    }
+
+    [Fact]
+    public async Task SubscribeAsync_MultiHost_FansOutByResolvedHost()
+    {
+        var driver = new FakeAlarmSource();
+        var resolver = new StubResolver(new Dictionary<string, string>
+        {
+            ["src-1"] = "plc-a",
+            ["src-2"] = "plc-b",
+            ["src-3"] = "plc-a",
+        });
+        var surface = NewSurface(driver, defaultHost: "default-ignored", resolver: resolver);
+
+        var handles = await surface.SubscribeAsync(["src-1", "src-2", "src-3"], CancellationToken.None);
+
+        handles.Count.ShouldBe(2);                 // one per distinct host
+        driver.SubscribeCallCount.ShouldBe(2);     // one driver call per host
+    }
+
+    [Fact]
+    public async Task AcknowledgeAsync_DoesNotRetry_OnFailure()
+    {
+        var driver = new FakeAlarmSource { AcknowledgeShouldThrow = true };
+        var surface = NewSurface(driver, defaultHost: "h1");
+
+        await Should.ThrowAsync<InvalidOperationException>(() =>
+            surface.AcknowledgeAsync([new AlarmAcknowledgeRequest("s", "c", null)], CancellationToken.None));
+
+        driver.AcknowledgeCallCount.ShouldBe(1, "AlarmAcknowledge must not retry — decision #143");
+    }
+
+    [Fact]
+    public async Task SubscribeAsync_Retries_Transient_Failures()
+    {
+        var driver = new FakeAlarmSource { SubscribeFailuresBeforeSuccess = 2 };
+        var surface = NewSurface(driver, defaultHost: "h1");
+
+        await surface.SubscribeAsync(["src"], CancellationToken.None);
+
+        driver.SubscribeCallCount.ShouldBe(3, "AlarmSubscribe retries by default — decision #143");
+    }
+
+    private static AlarmSurfaceInvoker NewSurface(
+        IAlarmSource driver,
+        string defaultHost,
+        IPerCallHostResolver? resolver = null)
+    {
+        var builder = new DriverResiliencePipelineBuilder();
+        var invoker = new CapabilityInvoker(builder, "drv-1", () => TierAOptions);
+        return new AlarmSurfaceInvoker(invoker, driver, defaultHost, resolver);
+    }
+
+    private sealed class FakeAlarmSource : IAlarmSource
+    {
+        public int SubscribeCallCount { get; private set; }
+        public int AcknowledgeCallCount { get; private set; }
+        public int SubscribeFailuresBeforeSuccess { get; set; }
+        public bool AcknowledgeShouldThrow { get; set; }
+        public IReadOnlyList<string> LastSubscribedIds { get; private set; } = [];
+
+        public Task<IAlarmSubscriptionHandle> SubscribeAlarmsAsync(
+            IReadOnlyList<string> sourceNodeIds, CancellationToken cancellationToken)
+        {
+            SubscribeCallCount++;
+            LastSubscribedIds = sourceNodeIds;
+            if (SubscribeCallCount <= SubscribeFailuresBeforeSuccess)
+                throw new InvalidOperationException("transient");
+            return Task.FromResult<IAlarmSubscriptionHandle>(new StubHandle($"h-{SubscribeCallCount}"));
+        }
+
+        public Task UnsubscribeAlarmsAsync(IAlarmSubscriptionHandle handle, CancellationToken cancellationToken)
+            => Task.CompletedTask;
+
+        public Task AcknowledgeAsync(
+            IReadOnlyList<AlarmAcknowledgeRequest> acknowledgements, CancellationToken cancellationToken)
+        {
+            AcknowledgeCallCount++;
+            if (AcknowledgeShouldThrow) throw new InvalidOperationException("ack boom");
+            return Task.CompletedTask;
+        }
+
+        public event EventHandler<AlarmEventArgs>? OnAlarmEvent { add { } remove { } }
+    }
+
+    private sealed record StubHandle(string DiagnosticId) : IAlarmSubscriptionHandle;
+
+    private sealed class StubResolver(Dictionary<string, string> map) : IPerCallHostResolver
+    {
+        public string ResolveHost(string fullReference) => map[fullReference];
+    }
+}