feat(configdb): add RowVersion to live-edit entities

Phase 1a of the v2 entity-model rewrite. Adds:

  public byte[] RowVersion { get; set; } = Array.Empty<byte>();

and the EF Core mapping

  e.Property(x => x.RowVersion).IsRowVersion();

to 12 live-edit entities:

  Equipment, DriverInstance, Device, Tag, PollGroup, Namespace,
  UnsArea, UnsLine, NodeAcl, Script, VirtualTag, ScriptedAlarm

These are the entities that v2 admins will edit directly via
AdminOperationsActor (no draft staging). RowVersion enables
last-write-wins detection when two operators race on the same row.

GenerationId FKs are still in place on these entities (removed in Task 14b);
this commit only adds the rowversion column so the migration in Task 14f can
emit ADD COLUMN before DROP FK as a single atomic step.

src/Core/ZB.MOM.WW.OtOpcUa.Configuration/Entities/ScriptedAlarm.cs

@@ -55,5 +55,8 @@ public sealed class ScriptedAlarm
 
     public bool Enabled { get; set; } = true;
 
+    /// <summary>Optimistic concurrency token for last-write-wins detection in the v2 live-edit model.</summary>
+    public byte[] RowVersion { get; set; } = Array.Empty<byte>();
+
     public ConfigGeneration? Generation { get; set; }
 }