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/Client/ZB.MOM.WW.OtOpcUa.Client.Shared/Adapters/ISubscriptionAdapter.cs

@@ -0,0 +1,56 @@
+using Opc.Ua;
+
+namespace ZB.MOM.WW.OtOpcUa.Client.Shared.Adapters;
+
+/// <summary>
+///     Abstracts OPC UA subscription and monitored item management.
+/// </summary>
+internal interface ISubscriptionAdapter : IDisposable
+{
+    /// <summary>
+    /// Gets the server-assigned subscription identifier for diagnostics and reconnect workflows.
+    /// </summary>
+    uint SubscriptionId { get; }
+
+    /// <summary>
+    ///     Adds a data-change monitored item and returns its client handle for tracking.
+    /// </summary>
+    /// <param name="nodeId">The node to monitor.</param>
+    /// <param name="samplingIntervalMs">The sampling interval in milliseconds.</param>
+    /// <param name="onDataChange">Callback when data changes. Receives (nodeIdString, DataValue).</param>
+    /// <param name="ct">Cancellation token.</param>
+    /// <returns>A client handle that can be used to remove the item.</returns>
+    Task<uint> AddDataChangeMonitoredItemAsync(NodeId nodeId, int samplingIntervalMs,
+        Action<string, DataValue> onDataChange, CancellationToken ct = default);
+
+    /// <summary>
+    ///     Removes a previously added monitored item by its client handle.
+    /// </summary>
+    /// <param name="clientHandle">The client handle returned when the monitored item was created.</param>
+    /// <param name="ct">The cancellation token that aborts the monitored-item removal.</param>
+    Task RemoveMonitoredItemAsync(uint clientHandle, CancellationToken ct = default);
+
+    /// <summary>
+    ///     Adds an event monitored item with the given event filter.
+    /// </summary>
+    /// <param name="nodeId">The node to monitor for events.</param>
+    /// <param name="samplingIntervalMs">The sampling interval.</param>
+    /// <param name="filter">The event filter defining which fields to select.</param>
+    /// <param name="onEvent">Callback when events arrive. Receives the event field list.</param>
+    /// <param name="ct">Cancellation token.</param>
+    /// <returns>A client handle for the monitored item.</returns>
+    Task<uint> AddEventMonitoredItemAsync(NodeId nodeId, int samplingIntervalMs, EventFilter filter,
+        Action<EventFieldList> onEvent, CancellationToken ct = default);
+
+    /// <summary>
+    ///     Requests a condition refresh for this subscription.
+    /// </summary>
+    /// <param name="ct">The cancellation token that aborts the condition refresh request.</param>
+    Task ConditionRefreshAsync(CancellationToken ct = default);
+
+    /// <summary>
+    ///     Removes all monitored items and deletes the subscription.
+    /// </summary>
+    /// <param name="ct">The cancellation token that aborts subscription deletion.</param>
+    Task DeleteAsync(CancellationToken ct = default);
+}