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/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Historian.Wonderware/Backend/HistorianConfiguration.cs

@@ -0,0 +1,38 @@
+using System.Collections.Generic;
+
+namespace ZB.MOM.WW.OtOpcUa.Driver.Historian.Wonderware.Backend
+{
+    /// <summary>
+    ///     Wonderware Historian SDK configuration. Populated from environment variables at Host
+    ///     startup (see <c>Program.cs</c>) or from the Proxy's <c>DriverInstance.DriverConfig</c>
+    ///     section passed during OpenSession. Kept OPC-UA-free — the Proxy side owns UA translation.
+    /// </summary>
+    public sealed class HistorianConfiguration
+    {
+        public bool Enabled { get; set; } = false;
+
+        /// <summary>Single-node fallback when <see cref="ServerNames"/> is empty.</summary>
+        public string ServerName { get; set; } = "localhost";
+
+        /// <summary>
+        ///     Ordered cluster nodes. When non-empty, the data source tries each in order on connect,
+        ///     falling through to the next on failure. A failed node is placed in cooldown for
+        ///     <see cref="FailureCooldownSeconds"/> before being re-eligible.
+        /// </summary>
+        public List<string> ServerNames { get; set; } = new();
+
+        public int FailureCooldownSeconds { get; set; } = 60;
+        public bool IntegratedSecurity { get; set; } = true;
+        public string? UserName { get; set; }
+        public string? Password { get; set; }
+        public int Port { get; set; } = 32568;
+        public int CommandTimeoutSeconds { get; set; } = 30;
+        public int MaxValuesPerRead { get; set; } = 10000;
+
+        /// <summary>
+        ///     Outer safety timeout applied to sync-over-async Historian operations. Must be
+        ///     comfortably larger than <see cref="CommandTimeoutSeconds"/>.
+        /// </summary>
+        public int RequestTimeoutSeconds { get; set; } = 60;
+    }
+}