fix(opcuaserver): chunked, per-item-isolated WriteValues with typed partial-failure outcome

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

@@ -9,7 +9,8 @@ namespace ZB.MOM.WW.OtOpcUa.OpcUaServer.Tests;
 /// <summary>
 ///     OpcUaServer-004 — a fresh <see cref="OtOpcUaNodeManager"/> whose <c>CreateAddressSpace</c> has NOT
 ///     yet run (i.e. the server has not started) has a null <c>_root</c>. Every public address-space mutator
-///     (<see cref="OtOpcUaNodeManager.WriteValue"/>, <see cref="OtOpcUaNodeManager.WriteAlarmCondition"/>,
+///     (<see cref="OtOpcUaNodeManager.WriteValue"/>, <see cref="OtOpcUaNodeManager.WriteValues"/>,
+///     <see cref="OtOpcUaNodeManager.WriteAlarmCondition"/>,
 ///     <see cref="OtOpcUaNodeManager.EnsureFolder"/>, <see cref="OtOpcUaNodeManager.EnsureVariable"/>,
 ///     <see cref="OtOpcUaNodeManager.MaterialiseAlarmCondition"/>) must now fail with a legible
 ///     <see cref="InvalidOperationException"/> instead of a bare NRE out of <c>ResolveParentFolder</c> /
@@ -78,6 +79,28 @@ public sealed class NodeManagerPreStartGuardTests : IDisposable
         }
     }
 
+    /// <summary>The batched mutator guards the same way — and it does so BEFORE its empty-batch early-return,
+    /// so a pre-start caller gets the legible failure regardless of what the batch happens to carry (an empty
+    /// batch returning quietly would make the guard depend on payload rather than on server state).</summary>
+    [Fact]
+    public async Task WriteValues_before_CreateAddressSpace_throws_InvalidOperationException()
+    {
+        var (host, nm) = await BuildPreStartNodeManagerAsync();
+        try
+        {
+            Should.Throw<InvalidOperationException>(() => nm.WriteValues(new[]
+            {
+                new ValueWrite("eq-1/temp", 1.0, OpcUaStatus.Good, DateTime.UtcNow, AddressSpaceRealm.Uns),
+            }));
+
+            Should.Throw<InvalidOperationException>(() => nm.WriteValues([]));
+        }
+        finally
+        {
+            await host.DisposeAsync();
+        }
+    }
+
     [Fact]
     public async Task MaterialiseAlarmCondition_before_CreateAddressSpace_throws_InvalidOperationException()
     {