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/Client/ZB.MOM.WW.OtOpcUa.Client.Shared.Tests/Fakes/FakeApplicationConfigurationFactory.cs

@@ -0,0 +1,38 @@
+using Opc.Ua;
+using ZB.MOM.WW.OtOpcUa.Client.Shared.Adapters;
+using ZB.MOM.WW.OtOpcUa.Client.Shared.Models;
+
+namespace ZB.MOM.WW.OtOpcUa.Client.Shared.Tests.Fakes;
+
+internal sealed class FakeApplicationConfigurationFactory : IApplicationConfigurationFactory
+{
+    public bool ThrowOnCreate { get; set; }
+    public int CreateCallCount { get; private set; }
+    public ConnectionSettings? LastSettings { get; private set; }
+
+    public Task<ApplicationConfiguration> CreateAsync(ConnectionSettings settings, CancellationToken ct)
+    {
+        CreateCallCount++;
+        LastSettings = settings;
+
+        if (ThrowOnCreate)
+            throw new InvalidOperationException("FakeApplicationConfigurationFactory configured to fail.");
+
+        var config = new ApplicationConfiguration
+        {
+            ApplicationName = "FakeClient",
+            ApplicationUri = "urn:localhost:FakeClient",
+            ApplicationType = ApplicationType.Client,
+            SecurityConfiguration = new SecurityConfiguration
+            {
+                AutoAcceptUntrustedCertificates = true
+            },
+            ClientConfiguration = new ClientConfiguration
+            {
+                DefaultSessionTimeout = settings.SessionTimeoutSeconds * 1000
+            }
+        };
+
+        return Task.FromResult(config);
+    }
+}