fix(opcua): UNS equipment folders browse by friendly Name, NodeId stays the logical Id

Equipment folder DisplayName was the colloquial MachineCode; the live rebuild (artifact
ReadEquipmentNode) + composer now use the UNS level-5 Name segment, matching Area/Line
folders + EquipmentNodeWalker. NodeId stays the logical EquipmentId so browse-path
resolution + ACLs are unaffected.

tests/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer.Tests/Phase7ComposerPurityTests.cs

@@ -75,6 +75,22 @@ public sealed class Phase7ComposerPurityTests
             .ShouldBe(new[] { "a", "m", "z" });
     }
 
+    /// <summary>Verifies UNS equipment folders browse by the friendly UNS <c>Name</c> segment
+    /// (not the colloquial MachineCode, not the logical EquipmentId) while the NodeId stays the
+    /// logical EquipmentId — so browse-path resolution + ACLs are unaffected (decision #3).</summary>
+    [Fact]
+    public void Equipment_node_DisplayName_is_the_UNS_Name_not_MachineCode()
+    {
+        var equipment = new[] { NewEquipment("filling-eq") }; // Name="filling-eq", MachineCode="FILLING-EQ"
+
+        var node = Phase7Composer.Compose(equipment, Array.Empty<DriverInstance>(), Array.Empty<ScriptedAlarm>())
+            .EquipmentNodes.ShouldHaveSingleItem();
+
+        node.EquipmentId.ShouldBe("filling-eq");    // NodeId stays the logical Id
+        node.DisplayName.ShouldBe("filling-eq");    // browse name = UNS Name segment
+        node.DisplayName.ShouldNotBe("FILLING-EQ"); // not the colloquial MachineCode
+    }
+
     private static Equipment NewEquipment(string id) => new()
     {
         EquipmentId = id,