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>

src/Server/ZB.MOM.WW.OtOpcUa.Server/History/HistoryRouter.cs

@@ -0,0 +1,71 @@
+using System.Collections.Concurrent;
+using ZB.MOM.WW.OtOpcUa.Core.Abstractions;
+
+namespace ZB.MOM.WW.OtOpcUa.Server.History;
+
+/// <summary>
+///     Default <see cref="IHistoryRouter"/> implementation.
+/// </summary>
+public sealed class HistoryRouter : IHistoryRouter
+{
+    private readonly ConcurrentDictionary<string, IHistorianDataSource> _registry =
+        new(StringComparer.OrdinalIgnoreCase);
+
+    private bool _disposed;
+
+    /// <inheritdoc />
+    public void Register(string fullReferencePrefix, IHistorianDataSource source)
+    {
+        ObjectDisposedException.ThrowIf(_disposed, this);
+        ArgumentNullException.ThrowIfNull(fullReferencePrefix);
+        ArgumentNullException.ThrowIfNull(source);
+
+        if (!_registry.TryAdd(fullReferencePrefix, source))
+        {
+            throw new InvalidOperationException(
+                $"A historian data source is already registered for prefix '{fullReferencePrefix}'.");
+        }
+    }
+
+    /// <inheritdoc />
+    public IHistorianDataSource? Resolve(string fullReference)
+    {
+        ObjectDisposedException.ThrowIf(_disposed, this);
+        ArgumentNullException.ThrowIfNull(fullReference);
+
+        // Longest-prefix match. Sources are typically a handful per server, so a linear
+        // scan is fine and avoids building a trie for a low-cardinality registry.
+        IHistorianDataSource? best = null;
+        var bestPrefixLength = -1;
+
+        foreach (var (prefix, source) in _registry)
+        {
+            if (fullReference.StartsWith(prefix, StringComparison.OrdinalIgnoreCase)
+                && prefix.Length > bestPrefixLength)
+            {
+                best = source;
+                bestPrefixLength = prefix.Length;
+            }
+        }
+
+        return best;
+    }
+
+    /// <summary>
+    ///     Disposes every registered source and prevents further registrations or
+    ///     resolutions. Sources may not all be disposable — null-safe disposal pattern.
+    /// </summary>
+    public void Dispose()
+    {
+        if (_disposed) return;
+        _disposed = true;
+
+        foreach (var source in _registry.Values)
+        {
+            try { source.Dispose(); }
+            catch { /* best-effort — server shutdown should not throw on a misbehaving source */ }
+        }
+
+        _registry.Clear();
+    }
+}