diff --git a/Directory.Build.props b/Directory.Build.props
index a8f9a2ff..1b08fc60 100644
--- a/Directory.Build.props
+++ b/Directory.Build.props
@@ -2,12 +2,10 @@
   <!--
     Defaults inherited by every csproj. Individual projects may override.
 
-    Deviation from the original v2 plan: TreatWarningsAsErrors is NOT set globally because the
-    pre-v2 test projects (e.g. Admin.Tests) carry 240+ xUnit1051 analyzer warnings that would
-    fail the build. New v2 projects (Commons, Cluster, ControlPlane, Runtime, OpcUaServer, AdminUI,
-    Host, Security) MUST opt in to <TreatWarningsAsErrors>true</TreatWarningsAsErrors> in their
-    own csproj. Once the legacy Admin/Server projects are deleted (Phase 10, Task 56), this can
-    be promoted back to a global default.
+    TreatWarningsAsErrors is NOT set globally because test projects carry analyzer warnings
+    (e.g. xUnit1051) that would fail the build. src/ projects opt in to
+    <TreatWarningsAsErrors>true</TreatWarningsAsErrors> in their own csproj (a few still pending;
+    see #606). Once every project is clean this can be promoted back to a global default.
   -->
   <PropertyGroup>
     <TargetFramework>net10.0</TargetFramework>
@@ -16,6 +14,20 @@
     <LangVersion>latest</LangVersion>
   </PropertyGroup>
 
+  <!--
+    OTOPCUA0001 is an ERROR under src/ (#595): production code must route capability calls through
+    CapabilityInvoker. src/ is currently clean; test projects keep it a Warning and suppress it
+    per-csproj where they call drivers at the wire level. The path test is relative to this file
+    so it does not depend on where the repo is checked out; backslashes normalised for Windows.
+  -->
+  <PropertyGroup>
+    <_OtRepoRoot>$([System.String]::Copy('$(MSBuildThisFileDirectory)').Replace('\','/'))</_OtRepoRoot>
+    <_OtProjPath>$([System.String]::Copy('$(MSBuildProjectFullPath)').Replace('\','/'))</_OtProjPath>
+  </PropertyGroup>
+  <PropertyGroup Condition="$(_OtProjPath.StartsWith('$(_OtRepoRoot)src/'))">
+    <WarningsAsErrors>$(WarningsAsErrors);OTOPCUA0001</WarningsAsErrors>
+  </PropertyGroup>
+
   <!--
     Wire the custom OTOPCUA0001 analyzer (UnwrappedCapabilityCallAnalyzer) into every project so
     the CapabilityInvoker-wrapping rule is enforced tree-wide, not just against the analyzer's own
diff --git a/global.json b/global.json
new file mode 100644
index 00000000..512142d2
--- /dev/null
+++ b/global.json
@@ -0,0 +1,6 @@
+{
+  "sdk": {
+    "version": "10.0.100",
+    "rollForward": "latestFeature"
+  }
+}
diff --git a/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.AbLegacy.IntegrationTests/ZB.MOM.WW.OtOpcUa.Driver.AbLegacy.IntegrationTests.csproj b/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.AbLegacy.IntegrationTests/ZB.MOM.WW.OtOpcUa.Driver.AbLegacy.IntegrationTests.csproj
index aa6471d7..7d1abd20 100644
--- a/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.AbLegacy.IntegrationTests/ZB.MOM.WW.OtOpcUa.Driver.AbLegacy.IntegrationTests.csproj
+++ b/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.AbLegacy.IntegrationTests/ZB.MOM.WW.OtOpcUa.Driver.AbLegacy.IntegrationTests.csproj
@@ -9,6 +9,12 @@
         <RootNamespace>ZB.MOM.WW.OtOpcUa.Driver.AbLegacy.IntegrationTests</RootNamespace>
     </PropertyGroup>
 
+    <!-- OTOPCUA0001 (#595): these suites call driver capabilities directly at the wire level on purpose;
+         the CapabilityInvoker-wrapping rule applies to production code only (src/ fails the build on it). -->
+    <PropertyGroup>
+        <NoWarn>$(NoWarn);OTOPCUA0001</NoWarn>
+    </PropertyGroup>
+
     <ItemGroup>
         <PackageReference Include="xunit.v3"/>
         <PackageReference Include="Shouldly"/>
diff --git a/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.AbLegacy.Tests/ZB.MOM.WW.OtOpcUa.Driver.AbLegacy.Tests.csproj b/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.AbLegacy.Tests/ZB.MOM.WW.OtOpcUa.Driver.AbLegacy.Tests.csproj
index a2b220f3..ae370b85 100644
--- a/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.AbLegacy.Tests/ZB.MOM.WW.OtOpcUa.Driver.AbLegacy.Tests.csproj
+++ b/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.AbLegacy.Tests/ZB.MOM.WW.OtOpcUa.Driver.AbLegacy.Tests.csproj
@@ -9,6 +9,12 @@
         <RootNamespace>ZB.MOM.WW.OtOpcUa.Driver.AbLegacy.Tests</RootNamespace>
     </PropertyGroup>
 
+    <!-- OTOPCUA0001 (#595): these suites call driver capabilities directly at the wire level on purpose;
+         the CapabilityInvoker-wrapping rule applies to production code only (src/ fails the build on it). -->
+    <PropertyGroup>
+        <NoWarn>$(NoWarn);OTOPCUA0001</NoWarn>
+    </PropertyGroup>
+
     <ItemGroup>
         <PackageReference Include="xunit.v3"/>
         <PackageReference Include="Shouldly"/>
diff --git a/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Calculation.Tests/ZB.MOM.WW.OtOpcUa.Driver.Calculation.Tests.csproj b/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Calculation.Tests/ZB.MOM.WW.OtOpcUa.Driver.Calculation.Tests.csproj
index b3cbfe8b..a8a03087 100644
--- a/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Calculation.Tests/ZB.MOM.WW.OtOpcUa.Driver.Calculation.Tests.csproj
+++ b/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Calculation.Tests/ZB.MOM.WW.OtOpcUa.Driver.Calculation.Tests.csproj
@@ -9,6 +9,12 @@
         <RootNamespace>ZB.MOM.WW.OtOpcUa.Driver.Calculation.Tests</RootNamespace>
     </PropertyGroup>
 
+    <!-- OTOPCUA0001 (#595): these suites call driver capabilities directly at the wire level on purpose;
+         the CapabilityInvoker-wrapping rule applies to production code only (src/ fails the build on it). -->
+    <PropertyGroup>
+        <NoWarn>$(NoWarn);OTOPCUA0001</NoWarn>
+    </PropertyGroup>
+
     <ItemGroup>
         <PackageReference Include="xunit.v3"/>
         <PackageReference Include="Shouldly"/>
diff --git a/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.FOCAS.IntegrationTests/ZB.MOM.WW.OtOpcUa.Driver.FOCAS.IntegrationTests.csproj b/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.FOCAS.IntegrationTests/ZB.MOM.WW.OtOpcUa.Driver.FOCAS.IntegrationTests.csproj
index a6ec89da..80d04ce6 100644
--- a/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.FOCAS.IntegrationTests/ZB.MOM.WW.OtOpcUa.Driver.FOCAS.IntegrationTests.csproj
+++ b/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.FOCAS.IntegrationTests/ZB.MOM.WW.OtOpcUa.Driver.FOCAS.IntegrationTests.csproj
@@ -9,6 +9,12 @@
         <RootNamespace>ZB.MOM.WW.OtOpcUa.Driver.FOCAS.IntegrationTests</RootNamespace>
     </PropertyGroup>
 
+    <!-- OTOPCUA0001 (#595): these suites call driver capabilities directly at the wire level on purpose;
+         the CapabilityInvoker-wrapping rule applies to production code only (src/ fails the build on it). -->
+    <PropertyGroup>
+        <NoWarn>$(NoWarn);OTOPCUA0001</NoWarn>
+    </PropertyGroup>
+
     <ItemGroup>
         <PackageReference Include="xunit.v3"/>
         <PackageReference Include="Shouldly"/>
diff --git a/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.FOCAS.Tests/ZB.MOM.WW.OtOpcUa.Driver.FOCAS.Tests.csproj b/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.FOCAS.Tests/ZB.MOM.WW.OtOpcUa.Driver.FOCAS.Tests.csproj
index 4a98f116..c4f4be54 100644
--- a/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.FOCAS.Tests/ZB.MOM.WW.OtOpcUa.Driver.FOCAS.Tests.csproj
+++ b/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.FOCAS.Tests/ZB.MOM.WW.OtOpcUa.Driver.FOCAS.Tests.csproj
@@ -9,6 +9,12 @@
         <RootNamespace>ZB.MOM.WW.OtOpcUa.Driver.FOCAS.Tests</RootNamespace>
     </PropertyGroup>
 
+    <!-- OTOPCUA0001 (#595): these suites call driver capabilities directly at the wire level on purpose;
+         the CapabilityInvoker-wrapping rule applies to production code only (src/ fails the build on it). -->
+    <PropertyGroup>
+        <NoWarn>$(NoWarn);OTOPCUA0001</NoWarn>
+    </PropertyGroup>
+
     <ItemGroup>
         <PackageReference Include="xunit.v3"/>
         <PackageReference Include="Shouldly"/>
diff --git a/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Tests/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Tests.csproj b/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Tests/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Tests.csproj
index c8df6dcc..39628bce 100644
--- a/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Tests/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Tests.csproj
+++ b/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Tests/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Tests.csproj
@@ -9,6 +9,12 @@
         <RootNamespace>ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Tests</RootNamespace>
     </PropertyGroup>
 
+    <!-- OTOPCUA0001 (#595): these suites call driver capabilities directly at the wire level on purpose;
+         the CapabilityInvoker-wrapping rule applies to production code only (src/ fails the build on it). -->
+    <PropertyGroup>
+        <NoWarn>$(NoWarn);OTOPCUA0001</NoWarn>
+    </PropertyGroup>
+
     <ItemGroup>
         <PackageReference Include="xunit.v3"/>
         <PackageReference Include="Shouldly"/>
diff --git a/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Modbus.IntegrationTests/ZB.MOM.WW.OtOpcUa.Driver.Modbus.IntegrationTests.csproj b/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Modbus.IntegrationTests/ZB.MOM.WW.OtOpcUa.Driver.Modbus.IntegrationTests.csproj
index 67092175..fcfa9d58 100644
--- a/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Modbus.IntegrationTests/ZB.MOM.WW.OtOpcUa.Driver.Modbus.IntegrationTests.csproj
+++ b/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Modbus.IntegrationTests/ZB.MOM.WW.OtOpcUa.Driver.Modbus.IntegrationTests.csproj
@@ -9,6 +9,12 @@
         <RootNamespace>ZB.MOM.WW.OtOpcUa.Driver.Modbus.IntegrationTests</RootNamespace>
     </PropertyGroup>
 
+    <!-- OTOPCUA0001 (#595): these suites call driver capabilities directly at the wire level on purpose;
+         the CapabilityInvoker-wrapping rule applies to production code only (src/ fails the build on it). -->
+    <PropertyGroup>
+        <NoWarn>$(NoWarn);OTOPCUA0001</NoWarn>
+    </PropertyGroup>
+
     <ItemGroup>
         <PackageReference Include="xunit.v3"/>
         <PackageReference Include="Shouldly"/>
diff --git a/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Modbus.Tests/ZB.MOM.WW.OtOpcUa.Driver.Modbus.Tests.csproj b/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Modbus.Tests/ZB.MOM.WW.OtOpcUa.Driver.Modbus.Tests.csproj
index e4ff8cf9..980a367b 100644
--- a/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Modbus.Tests/ZB.MOM.WW.OtOpcUa.Driver.Modbus.Tests.csproj
+++ b/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Modbus.Tests/ZB.MOM.WW.OtOpcUa.Driver.Modbus.Tests.csproj
@@ -9,6 +9,12 @@
         <RootNamespace>ZB.MOM.WW.OtOpcUa.Driver.Modbus.Tests</RootNamespace>
     </PropertyGroup>
 
+    <!-- OTOPCUA0001 (#595): these suites call driver capabilities directly at the wire level on purpose;
+         the CapabilityInvoker-wrapping rule applies to production code only (src/ fails the build on it). -->
+    <PropertyGroup>
+        <NoWarn>$(NoWarn);OTOPCUA0001</NoWarn>
+    </PropertyGroup>
+
     <ItemGroup>
         <PackageReference Include="xunit.v3"/>
         <PackageReference Include="Shouldly"/>
diff --git a/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Mqtt.Tests/ZB.MOM.WW.OtOpcUa.Driver.Mqtt.Tests.csproj b/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Mqtt.Tests/ZB.MOM.WW.OtOpcUa.Driver.Mqtt.Tests.csproj
index d734cfed..4479ced1 100644
--- a/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Mqtt.Tests/ZB.MOM.WW.OtOpcUa.Driver.Mqtt.Tests.csproj
+++ b/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Mqtt.Tests/ZB.MOM.WW.OtOpcUa.Driver.Mqtt.Tests.csproj
@@ -9,6 +9,12 @@
         <RootNamespace>ZB.MOM.WW.OtOpcUa.Driver.Mqtt.Tests</RootNamespace>
     </PropertyGroup>
 
+    <!-- OTOPCUA0001 (#595): these suites call driver capabilities directly at the wire level on purpose;
+         the CapabilityInvoker-wrapping rule applies to production code only (src/ fails the build on it). -->
+    <PropertyGroup>
+        <NoWarn>$(NoWarn);OTOPCUA0001</NoWarn>
+    </PropertyGroup>
+
     <ItemGroup>
         <PackageReference Include="xunit.v3"/>
         <PackageReference Include="Shouldly"/>
diff --git a/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.OpcUaClient.IntegrationTests/ZB.MOM.WW.OtOpcUa.Driver.OpcUaClient.IntegrationTests.csproj b/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.OpcUaClient.IntegrationTests/ZB.MOM.WW.OtOpcUa.Driver.OpcUaClient.IntegrationTests.csproj
index 1ea5b21d..34da9208 100644
--- a/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.OpcUaClient.IntegrationTests/ZB.MOM.WW.OtOpcUa.Driver.OpcUaClient.IntegrationTests.csproj
+++ b/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.OpcUaClient.IntegrationTests/ZB.MOM.WW.OtOpcUa.Driver.OpcUaClient.IntegrationTests.csproj
@@ -9,6 +9,12 @@
         <RootNamespace>ZB.MOM.WW.OtOpcUa.Driver.OpcUaClient.IntegrationTests</RootNamespace>
     </PropertyGroup>
 
+    <!-- OTOPCUA0001 (#595): these suites call driver capabilities directly at the wire level on purpose;
+         the CapabilityInvoker-wrapping rule applies to production code only (src/ fails the build on it). -->
+    <PropertyGroup>
+        <NoWarn>$(NoWarn);OTOPCUA0001</NoWarn>
+    </PropertyGroup>
+
     <ItemGroup>
         <PackageReference Include="xunit.v3"/>
         <PackageReference Include="Shouldly"/>
diff --git a/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.OpcUaClient.Tests/ZB.MOM.WW.OtOpcUa.Driver.OpcUaClient.Tests.csproj b/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.OpcUaClient.Tests/ZB.MOM.WW.OtOpcUa.Driver.OpcUaClient.Tests.csproj
index 5f8839d5..a1f497e6 100644
--- a/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.OpcUaClient.Tests/ZB.MOM.WW.OtOpcUa.Driver.OpcUaClient.Tests.csproj
+++ b/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.OpcUaClient.Tests/ZB.MOM.WW.OtOpcUa.Driver.OpcUaClient.Tests.csproj
@@ -9,6 +9,12 @@
         <RootNamespace>ZB.MOM.WW.OtOpcUa.Driver.OpcUaClient.Tests</RootNamespace>
     </PropertyGroup>
 
+    <!-- OTOPCUA0001 (#595): these suites call driver capabilities directly at the wire level on purpose;
+         the CapabilityInvoker-wrapping rule applies to production code only (src/ fails the build on it). -->
+    <PropertyGroup>
+        <NoWarn>$(NoWarn);OTOPCUA0001</NoWarn>
+    </PropertyGroup>
+
     <ItemGroup>
         <PackageReference Include="xunit.v3"/>
         <PackageReference Include="Shouldly"/>
diff --git a/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.TwinCAT.IntegrationTests/ZB.MOM.WW.OtOpcUa.Driver.TwinCAT.IntegrationTests.csproj b/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.TwinCAT.IntegrationTests/ZB.MOM.WW.OtOpcUa.Driver.TwinCAT.IntegrationTests.csproj
index a5dfdf3b..74f23c46 100644
--- a/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.TwinCAT.IntegrationTests/ZB.MOM.WW.OtOpcUa.Driver.TwinCAT.IntegrationTests.csproj
+++ b/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.TwinCAT.IntegrationTests/ZB.MOM.WW.OtOpcUa.Driver.TwinCAT.IntegrationTests.csproj
@@ -9,6 +9,12 @@
         <RootNamespace>ZB.MOM.WW.OtOpcUa.Driver.TwinCAT.IntegrationTests</RootNamespace>
     </PropertyGroup>
 
+    <!-- OTOPCUA0001 (#595): these suites call driver capabilities directly at the wire level on purpose;
+         the CapabilityInvoker-wrapping rule applies to production code only (src/ fails the build on it). -->
+    <PropertyGroup>
+        <NoWarn>$(NoWarn);OTOPCUA0001</NoWarn>
+    </PropertyGroup>
+
     <ItemGroup>
         <PackageReference Include="xunit.v3"/>
         <PackageReference Include="Shouldly"/>
diff --git a/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.TwinCAT.Tests/ZB.MOM.WW.OtOpcUa.Driver.TwinCAT.Tests.csproj b/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.TwinCAT.Tests/ZB.MOM.WW.OtOpcUa.Driver.TwinCAT.Tests.csproj
index 1f8f0313..fd7dacec 100644
--- a/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.TwinCAT.Tests/ZB.MOM.WW.OtOpcUa.Driver.TwinCAT.Tests.csproj
+++ b/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.TwinCAT.Tests/ZB.MOM.WW.OtOpcUa.Driver.TwinCAT.Tests.csproj
@@ -9,6 +9,12 @@
         <RootNamespace>ZB.MOM.WW.OtOpcUa.Driver.TwinCAT.Tests</RootNamespace>
     </PropertyGroup>
 
+    <!-- OTOPCUA0001 (#595): these suites call driver capabilities directly at the wire level on purpose;
+         the CapabilityInvoker-wrapping rule applies to production code only (src/ fails the build on it). -->
+    <PropertyGroup>
+        <NoWarn>$(NoWarn);OTOPCUA0001</NoWarn>
+    </PropertyGroup>
+
     <ItemGroup>
         <PackageReference Include="xunit.v3"/>
         <PackageReference Include="Shouldly"/>