PR 4.0 — Driver.Galaxy project skeleton + factory

New in-process .NET 10 driver project at
src/ZB.MOM.WW.OtOpcUa.Driver.Galaxy/. The Tier-A replacement for
Driver.Galaxy.Host + Driver.Galaxy.Proxy. PR 4.0 ships only the IDriver
shape + factory + options; capability bodies (browse, read, write,
subscribe, deploy-watch, host probes) land in PRs 4.1–4.7.

Files:
- Driver.Galaxy.csproj — net10 x64, AnyCPU+x64 platforms, references
  Core.Abstractions + Core. No MxGatewayClient ProjectReference yet — that
  comes in PR 4.2 once the gw NuGet package is wired (the user is
  shipping mxaccessgw on a parallel track).
- Config/GalaxyDriverOptions.cs — nested record hierarchy
  (Gateway/MxAccess/Repository/Reconnect) mirroring the JSON shape spelled
  out in lmx_mxgw_impl.md PR 4.0 acceptance section.
- GalaxyDriver.cs — minimal IDriver impl. Initialize/Shutdown toggle
  DriverHealth between Healthy/Unknown; Reinitialize bumps the timestamp;
  GetMemoryFootprint=0 (PR 4.4 wires SubscriptionRegistry size);
  FlushOptionalCachesAsync no-op. Logs intent on lifecycle calls so
  partial deployments are diagnosable.
- GalaxyDriverFactoryExtensions.cs — JSON parser, default fill-ins,
  validation throw on missing required fields. Driver type name
  "GalaxyMxGateway" intentionally distinct from legacy "Galaxy" so both
  factories coexist during parity testing (Phase 5). PR 4.W's
  Galaxy:Backend switch picks one or the other.

Tests:
- 10 tests in Driver.Galaxy.Tests covering minimal-config defaults, full
  override path, three required-field error cases, factory registration
  via DriverFactoryRegistry.TryGet, lifecycle health transitions
  (Init → Shutdown → Reinit), Dispose idempotency, and post-disposal
  ObjectDisposedException.

slnx: registers the new Driver.Galaxy + Driver.Galaxy.Tests projects.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/ZB.MOM.WW.OtOpcUa.Driver.Galaxy/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.csproj

@@ -0,0 +1,29 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <TargetFramework>net10.0</TargetFramework>
+        <Platforms>AnyCPU;x64</Platforms>
+        <Nullable>enable</Nullable>
+        <ImplicitUsings>enable</ImplicitUsings>
+        <LangVersion>latest</LangVersion>
+        <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
+        <GenerateDocumentationFile>true</GenerateDocumentationFile>
+        <NoWarn>$(NoWarn);CS1591</NoWarn>
+        <RootNamespace>ZB.MOM.WW.OtOpcUa.Driver.Galaxy</RootNamespace>
+    </PropertyGroup>
+
+    <ItemGroup>
+        <ProjectReference Include="..\ZB.MOM.WW.OtOpcUa.Core.Abstractions\ZB.MOM.WW.OtOpcUa.Core.Abstractions.csproj"/>
+        <ProjectReference Include="..\ZB.MOM.WW.OtOpcUa.Core\ZB.MOM.WW.OtOpcUa.Core.csproj"/>
+    </ItemGroup>
+
+    <ItemGroup>
+        <InternalsVisibleTo Include="ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Tests"/>
+    </ItemGroup>
+
+    <ItemGroup>
+        <NuGetAuditSuppress Include="https://github.com/advisories/GHSA-37gx-xxp4-5rgx"/>
+        <NuGetAuditSuppress Include="https://github.com/advisories/GHSA-w3x6-4m5h-cxqf"/>
+    </ItemGroup>
+
+</Project>