feat(client-cli): add ack/confirm/shelve alarm commands with service layer

Adds ConfirmAlarmAsync and ShelveAlarmAsync to IOpcUaClientService and
OpcUaClientService (mirroring the AcknowledgeAlarmAsync pattern: same
CallMethodAsync/ServiceResultException/StatusCode contract). Adds ShelveKind
enum (OneShot/Timed/Unshelve). Adds three new CLI commands — ack, confirm,
shelve — with hex EventId input and per-command argument validation.
Updates both fakes (CLI + UI) to implement the new interface members and
record calls. Adds 16 unit tests covering argument mapping, invalid-input
CommandException paths, bad-status output, and disconnect-in-finally.

src/Client/ZB.MOM.WW.OtOpcUa.Client.Shared/Models/ShelveKind.cs

@@ -0,0 +1,25 @@
+namespace ZB.MOM.WW.OtOpcUa.Client.Shared.Models;
+
+/// <summary>
+///     Shelve operations supported by the OPC UA Part 9 ShelvedStateMachine.
+/// </summary>
+public enum ShelveKind
+{
+    /// <summary>
+    /// OneShotShelve: suppresses the alarm for one occurrence. The alarm automatically
+    /// unshelves when it next returns to the inactive state.
+    /// </summary>
+    OneShot,
+
+    /// <summary>
+    /// TimedShelve: suppresses the alarm for a specified duration (seconds).
+    /// Requires a positive <c>shelvingTimeSeconds</c> argument.
+    /// </summary>
+    Timed,
+
+    /// <summary>
+    /// Unshelve: removes an active OneShotShelve or TimedShelve, returning the alarm
+    /// to its normal active-notification state.
+    /// </summary>
+    Unshelve
+}