test(adminui): E2E scaffolding for Test Connect + Reconnect + Status hub

- DriverTestConnectE2eTests: 3 scenarios (sim/wrong-port/black-hole)
  against the Modbus Docker fixture. Sim + wrong-port skip if fixture
  unreachable; black-hole uses ModbusDriverProbe directly (no fixture).
- DriverReconnectE2eTests: message round-trip through AdminOperationsActor
  cluster singleton — Ok=true + audit write, without live driver side effect.
- DriverStatusHubE2eTests: bridge-mocked fallback — spawns
  DriverStatusSignalRBridge in the harness ActorSystem with a mock
  IHubContext, publishes DriverHealthChanged to the driver-health DPS
  topic, asserts store upsert + hub SendAsync call.
- DockerFixtureAvailability helper: TCP-connect probe for skip guards.
- Moq 4.20.72 added to central package management for hub mocking.
- Design doc §8.3 replaced with concrete pre-ship operator runbook.

Directory.Packages.props

@@ -1,9 +1,7 @@
 <Project>
-
   <PropertyGroup>
     <ManagePackageVersionsCentrally>true</ManagePackageVersionsCentrally>
   </PropertyGroup>
-
   <ItemGroup>
     <PackageVersion Include="Akka" Version="1.5.62" />
     <PackageVersion Include="Akka.Cluster" Version="1.5.62" />
@@ -73,6 +71,7 @@
     <PackageVersion Include="Microsoft.IdentityModel.Tokens" Version="8.11.0" />
     <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.12.0" />
     <PackageVersion Include="Microsoft.Playwright" Version="1.51.0" />
+    <PackageVersion Include="Moq" Version="4.20.72" />
     <PackageVersion Include="Novell.Directory.Ldap.NETStandard" Version="3.6.0" />
     <PackageVersion Include="OPCFoundation.NetStandard.Opc.Ua.Client" Version="1.5.378.106" />
     <PackageVersion Include="OPCFoundation.NetStandard.Opc.Ua.Configuration" Version="1.5.378.106" />
@@ -99,5 +98,4 @@
     <PackageVersion Include="xunit.runner.visualstudio" Version="3.0.2" />
     <PackageVersion Include="xunit.v3" Version="1.1.0" />
   </ItemGroup>
-
-</Project>
+</Project>