fix(galaxy): complete PR 7.2 rename — use canonical GalaxyMxGateway driver type

The driver/factory/seed use 'GalaxyMxGateway' (legacy 'Galaxy' was retired),
but the AdminUI editor router, GalaxyDriverPage, address picker, identity
dropdown, the Galaxy browser/probe, and DraftValidator still keyed on 'Galaxy'.
Result: the seeded GalaxyMxGateway driver couldn't be edited ('no editor
registered'), UI-created Galaxy drivers wrote a type with no factory, and a
SystemPlatform-bound GalaxyMxGateway driver failed publish validation.
Align all stragglers to GalaxyMxGateway (+ failing-test-first DraftValidator
coverage). ShouldStub's 'Galaxy' legacy safety-net left intact.

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Browser/GalaxyDriverBrowser.cs

@@ -42,8 +42,10 @@ public sealed class GalaxyDriverBrowser : IDriverBrowser
         _logger = logger ?? NullLogger<GalaxyDriverBrowser>.Instance;
     }
 
-    /// <summary>Driver type key — matches the AdminUI's persisted "Galaxy" value.</summary>
-    public string DriverType => "Galaxy";
+    /// <summary>Driver type key — matches the AdminUI's persisted "GalaxyMxGateway" value.</summary>
+    // Hardcoded literal: this project references Driver.Galaxy.Contracts, not Driver.Galaxy,
+    // so GalaxyDriverFactoryExtensions.DriverTypeName isn't available here.
+    public string DriverType => "GalaxyMxGateway";
 
     /// <summary>
     ///     Deserializes a <see cref="GalaxyDriverOptions"/> blob, opens a transient

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy/GalaxyDriverProbe.cs

@@ -25,7 +25,7 @@ public sealed class GalaxyDriverProbe : IDriverProbe
 
     /// <inheritdoc />
     // Matches DriverInstance.DriverType strings set by the AdminUI's GalaxyDriverPage.
-    public string DriverType => "Galaxy";
+    public string DriverType => GalaxyDriverFactoryExtensions.DriverTypeName;
 
     /// <inheritdoc />
     public async Task<DriverProbeResult> ProbeAsync(string configJson, TimeSpan timeout, CancellationToken ct)