fix(lmxproxy): resolve write timeout — bypass OnWriteComplete callback for supervisory writes

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

lmxproxy/tests/ZB.MOM.WW.LmxProxy.Client.IntegrationTests/ZB.MOM.WW.LmxProxy.Client.IntegrationTests.csproj

@@ -24,6 +24,7 @@
     <None Update="appsettings.test.json">
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
     </None>
+    <Content Include="xunit.runner.json" CopyToOutputDirectory="PreserveNewest" />
   </ItemGroup>
 
 </Project>

lmxproxy/tests/ZB.MOM.WW.LmxProxy.Client.IntegrationTests/xunit.runner.json

@@ -0,0 +1,5 @@
+{
+  "$schema": "https://xunit.net/schema/current/xunit.runner.schema.json",
+  "parallelizeAssembly": false,
+  "parallelizeTestCollections": false
+}